Astronomy's topics - tribe.net

Space Elevator

Curry — Sat, 07 Nov 2009 02:50:31 GMT

Going Up? Top Floor, Space Elevator Games 2009
BREAKING NEWS: LaserMotive successfully qualified for the $900,000 prize! Their official speed was 3.72 m/s.
Though it's unlikely that anyone will be pressing the elevator button labeled 'Space' on one of the competitors' vehicles this year at the 2009 Space Elevator Games, there is hope that a winner will walk away with the $1.1 million prize. Three different teams will compete to see if any can send a laser powered vehicle up a thin but strong ribbon 1km (.6 miles) into the sky.(...)

http://www.universetoday.com/2009/11/04/going-up-top-floor-space-elevator-games-2009/

posted in Astronomy - 0 replies

Enceladus geysers

idea1407 — Wed, 04 Nov 2009 16:16:51 GMT

http://www.space.com/scienceastronomy/091104-enceladus-plumes.html

>"Water Geysers on Saturn Moon Take Center Stage
By Clara Moskowitz
Staff Writer
posted: 04 November 2009
09:32 am ET

Striking new photos of water-vapor geysers erupting from Saturn's moon Enceladus were beamed to Earth this week by NASA's Cassini spacecraft in orbit around the ringed planet.

Cassini made its deepest dive yet into the plumes pouring out from the moon's south pole on Nov. 2 during a planned flyby of Enceladus. The spacecraft approached within about 62 miles (100 km) of the moon's surface.

The powerful plumes, which contain water vapor, sodium and organic chemicals such as carbon dioxide, look a bit like the Old Faithful geyser in Yellowstone National Park. They have intrigued scientists because they suggest that a store of liquid water may be present beneath the moon's crust to give rise to the water vapor in the plumes. And if there is liquid water, there might be the possibility of some kind of alien life.

"If we can put the pieces together - a liquid ocean under the surface, heat driving the geysers and the organic molecules that are the building blocks of life - Enceladus might turn out to have the conditions that led to the origin of life on an earlier version of Earth," Cassini scientist Bonnie J. Buratti wrote on NASA's Jet Propulsion Laboratory blog.

The aim of the recent flyby - Cassini's seventh targeted swoop toward Enceladus - was to measure the size, mass, charge, speed and composition of the particles within the plume. The spacecraft made a quick approach traveling at about 18,000 mph (nearly 29,000 kph). In addition to the scientific data, the spacecraft returned new stunning snapshots showing the enigmatic geysers glowing in reflected sunlight against the dark backdrop of space.

"Not too bad being in orbit around Saturn, is it ?! ;-)" wrote Carolyn Porco, head of Cassini's imaging science team, via Twitter. Porco called the images "spectacular."

The joint U.S.-European Cassini spacecraft was launched in 1997 on a mission to orbit Saturn, and discovered the geysers on Enceladus in 2005. The spacecraft completed its primary mission in 2008 and is currently in the middle of an extended phase that runs through 2010. <CHECK THIS!!!

"This is the first time we've found activity on a moon this small," Buratti wrote, explaining that Enceladus is only about the width of Arizona, with a diameter of 310 miles (500 km)."<

pic:
http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=091104-enceladus-02.jpg&cap=This+raw%2C+unprocessed+image+of+Enceladus+was+taken+by+Cassini+on+Nov.+2%2C+2009.+Bright+plumes+of+water+vapor+are+visible+on+the+moon%27s+south+pole.+Credit%3A+NASA%2FJPL%2FSpace+Science+Institute

pic:
http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=091104-plumes-02.jpg∩=Geysers+on+the+Saturnian+moon+Enceladus.+Photo+taken+by+the+Cassini+spacecraft%27s+narrow-angle+camera+on+Nov.+1%2C+2009+using+a+spectral+filter+sensitive+to+wavelengths+of+near-infrared+light.+Credit%3A+NASA%2FJPL%2FSpace+Science+Institute

pic:
http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=091104-geysers-02.jpg∩=Bright+water-vapor+plumes+glisten+on+Enceladus+in+this+image+taken+in+visible+light+with+the+Cassini+spacecraft+narrow-angle+camera+on+Nov.+1%2C+2009.+Credit%3A+NASA%2FJPL%2FSpace+Science+Institute

posted in Astronomy - 1 reply

LCROSS has eyes on target

idea1407 — Fri, 11 Sep 2009 19:12:35 GMT

http://www.nasa.gov/home/hqnews/2009/sep/HQ_09-210_LCROSS_Crater_Selection.html

>"RELEASE : 09-210

NASA's LCROSS Reveals Target Crater For Lunar South Pole Impacts

MOFFETT FIELD, Calif. – NASA has selected a final destination for its Lunar Crater Observation and Sensing Satellite, or LCROSS, after a journey of nearly 5.6 million miles that included several orbits around Earth and the moon. The mission team announced Wednesday that Cabeus A will be the target crater for the LCROSS dual impacts scheduled for 7:30 a.m. EDT on Oct. 9, 2009. The crater was selected after an extensive review as the optimal location for LCROSS' evaluation of whether water ice exists at the lunar south pole.

LCROSS will search for water ice by sending its spent upper-stage Centaur rocket to impact the permanently shadowed polar crater. The satellite will fly into the plume of dust left by the impact and measure the properties before also colliding with the lunar surface. The LCROSS team selected Cabeus A based on a set of conditions that include proper debris plume illumination for visibility from Earth, a high concentration of hydrogen, and mature crater features such as a flat floor, gentle slopes and the absence of large boulders.

"The selection of Cabeus A was a result of a vigorous debate within the lunar science community that included review of the latest data from Earth-based observatories and our fellow lunar missions Kaguya, Chandrayaan-1, and the Lunar Reconnaissance Orbiter," said Anthony Colaprete, LCROSS project scientist and principle investigator at NASA’s Ames Research Center in Moffett Field, Calif. "The team is looking forward to the impacts and the wealth of information this unique mission will produce."

A cadre of professional astronomers using many of the Earth's most capable observatories is helping maximize the scientific return from the LCROSS impacts. These observatories include the Infrared Telescope Facility and Keck telescope in Hawaii; the Magdalena Ridge and Apache Ridge Observatories in New Mexico and the MMT Observatory in Arizona; the newly refurbished Hubble Space Telescope; and the Lunar Reconnaissance Orbiter, among others.

"These and several other telescopes participating in the LCROSS Observation Campaign will provide observations from different vantage points using different types of measurement techniques," said Jennifer Heldmann, lead for the LCROSS Observation Campaign at Ames. "These multiple observations will complement the LCROSS spacecraft data to help determine whether or not water ice exists in Cabeus A."

During a media briefing Sept. 11, Daniel Andrews, LCROSS project manager at Ames, provided a mission status update indicating the spacecraft is healthy and has enough fuel to successfully accomplish all mission objectives. Andrews also announced the dedication of the LCROSS mission to the memory of legendary news anchor, Walter Cronkite, who provided coverage of NASA's missions from the beginning of America's manned space program to the age of the space shuttle.

"Dad would sure be proud to be part, if just in name, of getting humans back up to the moon and beyond," said Chip Cronkite, son of the famed news anchor.

The LCROSS mission was selected in April 2006 as a mission manifested with the Lunar Reconnaissance Orbiter. Both missions launched on June 18, 2009 on an Atlas V from Cape Canaveral, Fla. The LCROSS mission and science operations are managed at Ames.

"The LCROSS team has long been preparing for its final destination on the moon, and we're looking forward to October 9," Andrews said. "The next 28 days will undoubtedly be very exciting.""<

posted in Astronomy - 5 replies

Frost-Covered Phoenix Lander Seen in Winter Images

Serge — Thu, 05 Nov 2009 01:19:46 GMT

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

News release: 2009-160, Nov. 4, 2009

The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/news.cfm?release=2009-160

PASADENA, Calif. -- Winter images of NASA's Phoenix Lander showing the lander shrouded in dry-ice frost on Mars have been captured with the High Resolution Imaging Science Experiment, or HiRISE camera, aboard NASA's Mars Reconnaissance Orbiter.

The HiRISE camera team at the University of Arizona, Tucson, captured one image of the Phoenix lander on July 30, 2009, and the other on Aug. 22, 2009. That's when the sun began peeking over the horizon of the northern polar plains during winter, the imaging team said. The first day of spring in the northern hemisphere began Oct. 26.

The images are available at http://hirise.lpl.arizona.edu/ESP_014393_2485 .

"We decided to try imaging the site despite the low light levels," said HiRISE team member Ingrid Spitale of the University of Arizona Lunar and Planetary Laboratory.

"The power of the HiRISE camera helped us see it even under these poor light conditions," added HiRISE team member Michael Mellon of the University of Colorado in Boulder, who was also on the Phoenix Mars Lander science team.

The HiRISE team targeted their camera at the known location of the lander to get the new images and compared them to a HiRISE image of the frost-free lander taken in June 2008. That enabled them to identify the hardware disguised by frost, despite the fact that their views were hindered by poor lighting and by atmospheric haze, which often obscures the surface at this location and season.

Carbon dioxide frost completely blankets the surface in both images. The amount of carbon dioxide frost builds as late winter transitions to early spring, so the layer of frost is thicker in the Aug. 22 image.

HiRISE scientists noted that brightness doesn't necessarily indicate the amount of frost seen in the images because of the way the images are processed to produce optimal contrast. Even the darker areas in the frost-covered images are still brighter than typical soil that surrounds the lander in frost-free images taken during the lander's prime mission in 2008.

Other factors that affect the relative brightness include the size of the individual grains of carbon dioxide ice, the amount of dust mixed with the ice, the amount of sunlight hitting the surface and different lighting angles and slopes, Spitale and Mellon said.

Studying these changes will help us understand the nature of the seasonal frost and winter weather patterns in this area of Mars.

Scientists predicted that the ice layer would reach maximum thickness in September 2009, but don't have images to confirm that because HiRISE camera operations were suspended when Mars Reconnaissance Orbiter entered an extended safe mode on Aug. 26.

The Phoenix Mars Lander ceased communications last November, after successfully completing its mission and returning unprecedented primary science phase and returning science data to Earth. During the first quarter of 2010, teams at JPL will listen to see if Phoenix is still able to communicate with Earth. Communication is not expected and is considered highly unlikely following the extended period of frost on the lander.

HiRISE is run from the Lunar and Planetary Laboratory's HiRISE Operations Center, on the University of Arizona campus. Planetary Sciences Professor Alfred McEwen is HiRISE principal investigator. Planetary Sciences Professor Peter Smith is principal investigator for the Phoenix Mars Lander mission. The Mars Reconnaissance Orbiter is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, for NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, based in Denver, is the prime contractor and built the spacecraft. Ball Aerospace Technologies Corp., of Boulder, Colo., built the HiRISE camera.

For more information about the mission, visit: http://www.nasa.gov/mro .

-end-

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posted in Astronomy - 2 replies

Galaxy cluster and Universe's Skeleton

idea1407 — Wed, 04 Nov 2009 03:16:44 GMT

http://www.space.com/scienceastronomy/091103-galaxies-cosmic-web.html

>"Huge Galaxy Cluster Hints at Universe's Skeleton
By SPACE.com staff

posted: 03 November 2009
08:42 am ET

A gigantic, previously unknown set of galaxies has been found in the distant universe, shedding light on the underlying skeleton of the cosmos.

"Matter is not distributed uniformly in the universe," said Masayuki Tanaka, an astronomer with the European Southern Observatory (ESO) who helped discover the galactic assemblage. "In our cosmic vicinity, stars form in galaxies and galaxies usually form groups and clusters of galaxies."

But those collections of matter are just small potatoes compared to larger structures long-theorized to exist.

"The most widely accepted cosmological theories predict that matter also clumps on a larger scale in the so-called 'cosmic web,' in which galaxies, embedded in filaments stretching between voids, create a gigantic wispy structure," Tanaka said.

These filaments are millions of light-years long and constitute the skeleton of the universe: Galaxies gather around them, and immense galaxy clusters form at their intersections, lurking like giant spiders waiting for more matter to digest.

Scientists have struggled, though, to explain how the filaments come into existence. While massive filamentary structures have often been observed at relatively small distances from us, solid proof of their existence in the more distant universe has been lacking until now.

The team led by Tanaka discovered a large structure around a distant cluster of galaxies in images they had taken earlier. They have now used two major ground-based telescopes to study this structure in greater detail, measuring the distances from Earth to more than 150 galaxies, and, hence, obtaining a three-dimensional view of the structure.

The spectroscopic observations, detailed in the Astronomy & Astrophysics Journal, were performed using the VIMOS instrument on ESO's Very Large Telescope in Chile and FOCAS on the Subaru Telescope in Hawaii, operated by the National Astronomical Observatory of Japan.

With these observations, the astronomers identified several groups of galaxies surrounding the main galaxy cluster.

The researchers were able to distinguish tens of such clumps, each typically ten times as massive as our own Milky Way galaxy — and some as much as a thousand times more massive — while they estimate that the mass of the cluster amounts to at least ten thousand times the mass of the Milky Way.

Some of the clumps are feeling the fatal gravitational pull of the cluster, and will eventually fall into it, the data suggested.

This information will allow scientists to explore how galaxies were affected by their environment at a time when the universe was much younger.

The filament is located about 6.7 billion light-years away from us and extends over at least 60 million light-years. The newly uncovered structure does probably extend farther, beyond the field probed by the team, and hence future observations have already been planned to obtain a definite measurement of its size."<

posted in Astronomy - 2 replies

Mercury's Seasons

idea1407 — Wed, 04 Nov 2009 04:01:44 GMT

http://www.space.com/scienceastronomy/091103-mercury-new-images.html

>"NASA Probe Sees Changing Seasons on Mercury
By Andrea Thompson
Senior Writer
posted: 03 November 2009
02:58 pm ET

A NASA spacecraft has spotted what appears to be changing seasons on Mercury and found much more iron on the surface of the small, rocky planet than previously thought.

The MESSENGER probe made the observations during its third flyby of Mercury on Sept. 29, when it took a host of measurements and images of the innermost planet's surface and atmosphere. Only about half of the planned measurements were made because of a data glitch that affected the spacecraft during the flyby.

The $446 million probe's third flyby brought it within 142 miles (228 km) of Mercury's surface to cover more uncharted terrain, leaving 98 percent of the planet now mapped. The flyby was also a gravity assist meant to guide the spacecraft into orbit around the planet in 2011.

Tenuous exosphere

Mercury's atmosphere is what scientists call an "exosphere," and is made up of atoms kicked up from the surface. It is very tenuous and has a very low density, meaning atoms in the atmosphere rarely run into each other. It also has a tail that streams away from the planet in the opposite direction of the sun.

MESSENGER looked at differences in three atoms in the exosphere — sodium, calcium and magnesium — between the probe's three flybys. They detected much less sodium during the third flyby than they had during the second.

"While this is dramatic, it isn't totally unexpected," Vervack said. This is because radiation pressures from the sun change as Mercury moves through its orbit, which changes the amount of sodium liberated from the surface.

In essence, Mercury's atmosphere experiences seasonal effects during the planet's orbit.

Calcium and magnesium showed less variation between "seasons" than did sodium, showing that different atoms "are going to have their own unique seasonal varations," Vervack said.

Understanding these seasonal differences will help scientists understand how surface material is lost and how the surface has changed over time.

Mercury's atmosphere is "the end product of a few billion years of these processes, they never stop," said mission scientist Ronald Vervack, Jr., of The Johns Hopkins University Applied Physics Laboratory (JHUAPL) in Laurel, Md.

Surface surprises

The MESSENGER flybys also provided the first direct measurements of the amounts of certain elements on Mercury's surface.

Mercury's surface has long thought to be deficient in the heavy metals iron and titanium on the basis of earlier observations, an ironic make-up considering that its heavy iron core makes up an estimated 60 percent of the planet's mass and makes it the densest of the solar system's rock planets.

MESSENGER's observations show that Mercury's surface actually possesses relatively high numbers of these elements — similar to the concentrations in the moon's nearside maria basalts — which could mean that models on the planets formation and evolution will need to be revised.

"That's a pretty exciting result for us," said David Lawrence, also of JHUAPL.

The third flyby also yielded new images of the surface that fill in as-yet unobserved areas. The spacecraft's cameras and instruments collected high-resolution and color images unveiling another 6 percent of the planet's surface never before seen at close range.

"We've done a good job on filling in most of that map," said Brett Denevi, imaging team member and postdoctoral researcher at Arizona State University in Tempe.

The flyby garnered images of a feature seen before, but not in enough detail to characterize it. It appears to be a bright area surrounding an irregular depression, with steep sides and an odd shape, "all of which are hallmarks of something like a volcanic vent," Denevi said.

Other images revealed a double-ring impact basin approximately 180 miles across. The basin is similar to a feature scientists call the Raditladi basin, which was viewed during the probe's first flyby of Mercury in January 2008.

"One similarity to Raditladi is its age, which has been estimated to be approximately one billion years old. Such an age is quite young for an impact basin, because most basins are about four times older," Denevi said. "The inner floor of this basin is even younger than the basin itself and differs in color from its surroundings. We may have found the youngest volcanic material on Mercury."

The spacecraft has completed nearly three-quarters of its 4.9-billion-mile journey to enter orbit around Mercury. The full trip will include more than 15 trips around the sun. In addition to flying by Mercury, the spacecraft flew past Earth in August 2005 and Venus in October 2006 and June 2007."<

Pic:
http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=091103-mercury-map-02.jpg&cap=Image+coverage+map+of+Mercury+after+the+third+MESSENGER+flyby.+he+nearly+complete+%2898+percent%29+coverage+now+leaves+unimaged+only+portions+of+the+polar+regions+before+MESSENGER+is+placed+into+orbit+about+Mercury+in+March+2011.+Credit%3A+JHU%2FAPL%2FNASA

posted in Astronomy - 1 reply

Galaxy Cluster 10 Billion Light Years Distant

Hummingbird — Thu, 22 Oct 2009 16:55:56 GMT

http://blogs.discovermagazine.com/badastronomy/2009/10/22/cluster-tucked-at-the-far-reaches-of-the-universe/

"A cluster of galaxies recently observed by three different telescopes now holds the record for the most distant ever seen: 10.2 billion light years, a solid billion light years farther away than the previous record holder!"

From Phil Plait's "Bad Astronomy" blog. One of the top notch blogs about astronomy on the internet.

posted in Astronomy - 5 replies

GRB, Fermi, Relativity and Quantum Mechanics - Observed!

idea1407 — Fri, 30 Oct 2009 23:03:56 GMT

a must see from NASA.

http://www.youtube.com/watch?v=1mkKhn53L68

posted in Astronomy - 0 replies

Robot Armada Might Scale New Worlds

Serge — Wed, 28 Oct 2009 04:55:53 GMT

Feature, Oct. 27, 2009

The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/features.cfm?feature=2343

An armada of robots may one day fly above the mountain tops of Saturn's moon Titan, cross its vast dunes and sail in its liquid lakes.
Wolfgang Fink, visiting associate in physics at the California Institute of Technology in Pasadena says we are on the brink of a great paradigm shift in planetary exploration, and the next round of robotic explorers will be nothing like what we see today.

"The way we explore tomorrow will be unlike any cup of tea we've ever tasted," said Fink, who was recently appointed as the Edward and Maria Keonjian Distinguished Professor in Microelectronics at the University of Arizona, Tucson. "We are departing from traditional approaches of a single robotic spacecraft with no redundancy that is Earth-commanded to one that allows for having multiple, expendable low-cost robots that can command themselves or other robots at various locations at the same time."

Fink and his team members at Caltech, the U.S. Geological Survey and the University of Arizona are developing autonomous software and have built a robotic test bed that can mimic a field geologist or astronaut, capable of working independently and as part of a larger team. This software will allow a robot to think on its own, identify problems and possible hazards, determine areas of interest and prioritize targets for a close-up look.

The way things work now, engineers command a rover or spacecraft to carry out certain tasks and then wait for them to be executed. They have little or no flexibility in changing their game plan as events unfold; for example, to image a landslide or cryovolcanic eruption as it happens, or investigate a methane outgassing event.

"In the future, multiple robots will be in the driver's seat," Fink said. These robots would share information in almost real time. This type of exploration may one day be used on a mission to Titan, Mars and other planetary bodies. Current proposals for Titan would use an orbiter, an air balloon and rovers or lake landers.

In this mission scenario, an orbiter would circle Titan with a global view of the moon, with an air balloon or airship floating overhead to provide a birds-eye view of mountain ranges, lakes and canyons. On the ground, a rover or lake lander would explore the moon's nooks and crannies. The orbiter would "speak" directly to the air balloon and command it to fly over a certain region for a closer look. This aerial balloon would be in contact with several small rovers on the ground and command them to move to areas identified from overhead.

"This type of exploration is referred to as tier-scalable reconnaissance," said Fink. "It's sort of like commanding a small army of robots operating in space, in the air and on the ground simultaneously."

A rover might report that it's seeing smooth rocks in the local vicinity, while the airship or orbiter could confirm that indeed the rover is in a dry riverbed -- unlike current missions, which focus only on a global view from far above but can't provide information on a local scale to tell the rover that indeed it is sitting in the middle of dry riverbed.

A current example of this type of exploration can best be seen at Mars with the communications relay between the rovers and orbiting spacecraft like the Mars Reconnaissance Orbiter. However, that information is just relayed and not shared amongst the spacecraft or used to directly control them.

"We are basically heading toward making robots that command other robots," said Fink, who is director of Caltech's Visual and Autonomous Exploration Systems Research Laboratory, where this work has taken place.

"One day an entire fleet of robots will be autonomously commanded at once. This armada of robots will be our eyes, ears, arms and legs in space, in the air, and on the ground, capable of responding to their environment without us, to explore and embrace the unknown," he added.

Papers describing this new exploration are published in the journal "Computer Methods and Programs in Biomedicine" and in the Proceedings of the SPIE.

For more information on this work, visit http://autonomy.caltech.edu . More information on JPL missions is at http://www.jpl.nasa.gov/ .

JPL is managed for NASA by the California Institute of Technology.

Media contact: Carolina Martinez/JPL 818-354-9382

-end-

From: subscription email

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JPL's 'Green' Space Flight Building Debuts with Ribbon-Cutting

Serge — Tue, 27 Oct 2009 03:08:50 GMT

Elena Mejia/Mark Petrovich 818-393-5467/393-4359
Jet Propulsion Laboratory, Pasadena, Calif.
Elena.Mejia@jpl.nasa.gov / Mark.Petrovich@jpl.nasa.gov

News release: 2009-157, Oct. 26, 2009

The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/news.cfm?release=2009-157

NASA's "greenest" building to date -- an environmentally friendly Flight Projects Center at NASA's Jet Propulsion Laboratory in Pasadena, Calif. -- is now open for business, following a ribbon-cutting ceremony today attended by lawmakers and local dignitaries.

The building houses missions during their design and development phases. It will enable engineers and scientists from various countries to collaborate more closely during these critical mission phases.

"It seems fitting that the new building, where teams will plan future space missions that use new technologies, also has the latest 'green' technologies to help JPL do its part to improve our environment here on Earth," said JPL Director Charles Elachi, who helped cut the ribbon at today's ceremony.

Also attending today's ceremony were U.S. Rep. David Drier; La Canada-Flintridge Mayor Laura Olhasso; staff representing U.S. Rep. Adam Schiff; and Caltech President Jean-Lou Chameau.

The building has received the "LEED Gold Certification" under the Leadership in Energy and Environmental Design rating system, set up by the non-profit U.S. Green Building Council. It is the first NASA building to achieve that certification. To qualify, buildings must meet several criteria. For example, they must make efficient use of water, energy and resources, and provide a healthy and comfortable indoor workspace.

The many "green" features of the new building include:

A living roof to keep the building cool in summer months and warm in the winter. Desert plants on the roof and other landscaping require 72 percent less water than a typical Southern California landscape design.

Outdoor lighting is used for safety purposes only and is directed toward the ground, reducing the amount of light pollution that escapes to the night sky.

Low-flow faucets and toilets reduce water use by 40 percent compared with typical fixtures.

Improved wall insulation, efficient chillers and boilers and window shading devices.

The paints and other surface materials have low levels of toxic fumes.

The heating and cooling system is "smart" -- it knows whether people are in a room and adjusts the temperature and ventilation accordingly.

The janitorial staff uses green cleaning products and practices.

More than 75 percent of the waste generated during construction of the new building was diverted from a landfill to a local recycling facility. Wood was acquired from Forest Stewardship Council-certified suppliers, ensuring sustainable harvesting of trees.

More information about the Leadership in Energy and Environmental Design rating system and the U.S. Green Building Council is online at http://www.usgbc.org .

More information about JPL is online at http://www.jpl.nasa.gov . The California Institute of Technology in Pasadena manages JPL for NASA.

- end -

From: subscription email

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Free Classes for Teachers: Lunar Certification and Marsbound, (NASA)

Serge — Mon, 26 Oct 2009 18:15:20 GMT

Oct. 26, 2009

What:
The NASA/JPL Education Resources Center is offering FREE classes!

Are you interested in Lunar Certification? This certification allows you to borrow actual lunar rock and soil samples as well as meteorite samples from NASA.

We are also offerring a class on the Marsbound Challenge to the red planet. You have $250 million dollars to plan a mission to the red planet. This game will challenge students to work together just as JPL engineers do. Marsbound meets many California state content standards in math as well as science and technology from 4th grade through high school.

When:
October 27 – Marsbound: 4 p.m. to 5:30 p.m.
November 12 – Lunar Certification: 4 p.m. to 6:00 p.m.

Where:
Educator Resource Center
1460 Holt Ave.
Pomona, CA 91767
909-397-4420

Directions:
Take the Indian Hill exit on U.S. 10. Go south until Indian Hill ends at Holt. Drive into the shopping center straight ahead. (Village @ Indian Hill Mall). Look for mall entrance number 3, park and enter the mall.

Parking is free.

How:
RSVP to the Education Resource Center at 909-397-4420.

See you there!

- end -

From: subscription email

posted in Astronomy - 2 replies

Astronomers do it Again: Find Organic Molecules Around Gas Planet

Serge — Wed, 21 Oct 2009 06:52:20 GMT

Feature, Oct. 20, 2009

The full version of this story with accompanying images is at: http://www.jpl.nasa.gov/news/features.cfm?feature=2340

Peering far beyond our solar system, NASA researchers have detected the basic chemistry for life in a second hot gas planet, advancing astronomers toward the goal of being able to characterize planets where life could exist. The planet is not habitable but it has the same chemistry that, if found around a rocky planet in the future, could indicate the presence of life.

"It's the second planet outside our solar system in which water, methane and carbon dioxide have been found, which are potentially important for biological processes in habitable planets," said researcher Mark Swain of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Detecting organic compounds in two exoplanets now raises the possibility that it will become commonplace to find planets with molecules that may be tied to life."

Swain and his co-investigators used data from two of NASA's orbiting Great Observatories, the Hubble Space Telescope and Spitzer Space Telescope, to study HD 209458b, a hot, gaseous giant planet bigger than Jupiter that orbits a sun-like star about 150 light years away in the constellation Pegasus. The new finding follows their breakthrough discovery in December 2008 of carbon dioxide around another hot, Jupiter-size planet, HD 189733b. Earlier Hubble and Spitzer observations of that planet had also revealed water vapor and methane.

The detections were made through spectroscopy, which splits light into its components to reveal the distinctive spectral signatures of different chemicals. Data from Hubble's near-infrared camera and multi-object spectrometer revealed the presence of the molecules, and data from Spitzer's photometer and infrared spectrometer measured their amounts.

"This demonstrates that we can detect the molecules that matter for life processes," said Swain. Astronomers can now begin comparing the two planetary atmospheres for differences and similarities. For example, the relative amounts of water and carbon dioxide in the two planets is similar, but HD 209458b shows a greater abundance of methane than HD 189733b. "The high methane abundance is telling us something," said Swain. "It could mean there was something special about the formation of this planet."

Other large, hot Jupiter-type planets can be characterized and compared using existing instruments, Swain said. This work will lay the groundwork for the type of analysis astronomers eventually will need to perform in shortlisting any promising rocky Earth-like planets where the signatures of organic chemicals might indicate the presence of life.

Rocky worlds are expected to be found by NASA's Kepler mission, which launched earlier this year, but astronomers believe we are a decade or so away from being able to detect any chemical signs of life on such a body.

If and when such Earth-like planets are found in the future, "the detection of organic compounds will not necessarily mean there's life on a planet, because there are other ways to generate such molecules," Swain said. "If we detect organic chemicals on a rocky, Earth-like planet, we will want to understand enough about the planet to rule out non-life processes that could have led to those chemicals being there."

"These objects are too far away to send probes to, so the only way we're ever going to learn anything about them is to point telescopes at them. Spectroscopy provides a powerful tool to determine their chemistry and dynamics."

You can follow the history of planet hunting from science fiction to science fact with NASA's PlanetQuest Historic Timeline at http://planetquest.jpl.nasa.gov/timeline/timeline.html .

This interactive web feature, developed by JPL, conveys the story of exoplanet exploration through a rich tapestry of words and images spanning thousands of years, beginning with the musings of ancient philosophers and continuing through the current era of space-based observations by NASA's Spitzer and Kepler missions. The timeline highlights milestones in culture, technology and science, and includes a planet counter that tracks the pace of exoplanet discoveries over time.

More information about exoplanets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov .

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency and is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The Space Telescope Science Institute, Baltimore, Md., conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for research in Astronomy, Inc., Washington, D.C.

JPL manages the Spitzer Space Telescope mission for NASA. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

-end-

Written by Mary Beth Murrill

Media contact: Whitney Clavin/Jet Propulsion Laboratory 818-354-4671

From: subscription email

posted in Astronomy - 3 replies

Glimpses of Solar System's edge

freetheweed — Thu, 15 Oct 2009 21:11:24 GMT

http://news.bbc.co.uk/2/hi/science/nature/8309179.stm

The first results from Nasa's Interstellar Boundary Explorer (Ibex) spacecraft have shown unexpected features at our Solar System's edge.

Ibex was launched nearly one year ago to map the heliosphere, the region of space defined by the extent of our Sun's solar wind.

Ibex's first glimpses show that the heliosphere is not shaped as many astronomers have believed.

A series of papers in the journal Science outlines the results.

Our Solar System is whipping around the centre of the galaxy. Just like a hand held out of a moving car, the Solar System feels a "wind" of particles from the region between our star and its nearest neighbours.

At the same time, the solar wind - a constant stream of fast-moving particles in all directions - blows outwards from the Sun.

The boundary at which the incoming and outgoing particles are at equivalent pressures, known as the heliopause, defines the heliosphere - the "bubble" in space generated by our own Sun's exhalations.

True shape

The true extent and shape of the heliosphere has been a subject of debate for more than half a century. Until now, the best clues came from the two Voyager spacecraft, which are believed to have passed through the heliopause at two different distances.

Through a process known as "charge exchange" at the heliosphere's edge, fast-moving neutral or uncharged particles are created, and it is these energetic neutral atoms or ENAs that the Ibex spacecraft aims to measure.

It orbits the Earth in a vast ellipse, gathering incoming ENAs flying back from the heliopause at a range of speeds.

What a number of researchers have found is that the flow of the ENAs is uneven, with a significantly higher flow in a "ribbon" across the sky.

"The Ibex results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region," said lead researcher Dr David McComas of the Southwest Research Institute in New Mexico.

"We expected to see small, gradual spatial variations at the interstellar boundary. However, Ibex is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky."

Near miss

These concentrations of incoming particles were just missed by the Voyager spacecraft, Dr McComas explained.

"The most astounding feature in the Ibex sky maps - the bright narrow ribbon - snakes through the sky between the Voyager spacecraft, where it remained completely undetected until now," he said.

Further measurements were made by the Cassini spacecraft orbiting Saturn. It too has a "camera" that can capture incoming neutral atoms, and also observed a ribbon-shaped region across the sky, but from ENAs moving at slightly different speeds.

What is clear is that the heliosphere is not shaped like a comet, as previously thought, with a head pointed at the oncoming interstellar medium and a tail of matter trailing behind.

The research groups agree that the magnetic field interactions at the heliopause have as-yet undetermined effects on the overall shape. But the exact shape, and the forces that cause it, are still a matter of debate between the teams.

INTERSTELLAR BOUNDARY EXPLORER (IBEX)

*Completes a large, elliptical orbit around the Earth
*Measures uncharged atoms that enter the Solar System from the interstellar medium
*Can detect hydrogen, helium, and oxygen moving at a wide range of speeds through the Solar System
*Results should explain how interstellar magnetic fields form our heliosphere

posted in Astronomy - 5 replies

32 new planets

Curry — Tue, 20 Oct 2009 15:14:17 GMT

October 19th, 2009
HARPS Discovers 32 New Exoplanets
Written by Nancy Atkinson ShareThis

Astronomers have found 32 new planets outside our solar system with the High Accuracy Radial Velocity Planet Searcher, better known as HARPS, the spectrograph for the European Southern Observatory's (ESO) 3.6-metre telescope. The number of known exoplanets is now at 406, and HARPS itself has discovered more than 75 exoplanets in 30 different planetary systems. Included in this most recent batch are several low-mass planets – so-called "Super Earths" about the size of Neptune. The image above is an artist's impression of a planet discovered that is 6 times the mass of Earth, which circles the low-mass host star, Gliese 667 C, at a distance equal to only 1/20th of the Earth-Sun distance. Two other planets were discovered previously around this star.

"HARPS is a unique, extremely high precision instrument that is ideal for discovering alien worlds," said ESO astronomer Stéphane Udry. “We have now completed our initial five-year program, which has succeeded well beyond our expectations.”

No Earth-like planets were discovered in this group that was announced today at an exoplanet conference in Portugal.

HARPS has facilitated the discovery of 24 of the 28 planets known with masses below 21 Earth masses. As with the previously detected super-Earths, most of the new low-mass candidates reside in multi-planet systems, with up to five planets per system. This new group includes a total of 11 planets with masses between 5 and 21 times that of Earth – and 9 in multi-planet systems — and increases the number of known low-mass planets by 30%.

HARPS uses the radial velocity technique which measures the back-and-forward motions of stars by detecting small changes in a star’s radial velocity as it wobbles slightly from a gentle gravitational pull from an otherwise unseen planet. HARPS can detect changes in velocity as small as 3.5 km/hour, a steady walking pace.

Notable discoveries by HARPS during the past five years include the first super-Earth in 2004 (around µ Ara; ESO 22/04); in 2006, the trio of Neptunes around HD 69830 (ESO 18/06); in 2007, Gliese 581d, the first super Earth in the habitable zone of a small star (ESO 22/07); and in 2009, the lightest exoplanet so far detected around a normal star, Gliese 581e (ESO 15/09). More recently, they found a potentially lava-covered world, with density similar to that of the Earth’s (ESO 33/09).

“These observations have given astronomers a great insight into the diversity of planetary systems and help us understand how they can form,” says team member Nuno Santos.

Source: ESO

Filed under: Extrasolar Planets

http://www.universetoday.com/2009/10/19/harps-discovers-32-new-exoplanets/

posted in Astronomy - 0 replies

NASA Finds Plume From LCROSS Impact

Hummingbird — Fri, 16 Oct 2009 23:50:02 GMT

http://www.space.com/scienceastronomy/091016-lcross-plume.html

NASA scientists have finally seen in their data a debris plume created by the impact of a moon probe last week.
The faint plume was seen in the data from the engineered crash one week after the impact of the LCROSS probe.
Scientists are hoping that analysis of the plume will show signs of water ice ejected from the probe's target crater, named Cabeus, at the lunar south pole.

posted in Astronomy - 1 reply

Enceladus water debate

idea1407 — Tue, 13 Oct 2009 22:08:10 GMT

http://www.space.com/scienceastronomy/091013-st-enceladus-debate.html

>"Hot Debate Rages Over Water on Saturn's Icy Moon

By Clara Moskowitz
Astrobiology Magazine
posted: 13 October 2009
08:50 am ET

The recent discovery of plumes containing water vapor erupting from the south pole of the frigid Saturnian moon Enceladus set off a firestorm of debate.

Many scientists thought the geysers of gaseous water must boil out of liquid water stored under the moon's surface, which would make Enceladus a promising candidate for life.

But a new study challenges that conclusion, arguing that the plumes could just as easily come from ice through the process of sublimation - the direct leap from the solid to gaseous state.

This conclusion may dampen Enceladus' astrobiology hopes, though it does not exclude the possibility of liquid water, and thus life, on the moon.

Cold Faithful

Enceladus' geysers were first spotted in 2005 by NASA's Cassini spacecraft, which was launched in 1997 on a mission to orbit Saturn. Shortly after the discovery, a research group led by Carolyn Porco, head of Cassini's imaging science team, calculated the ratio of water ice to vapor in the plumes. Cassini wasn't able to directly measure the masses of ice and vapor in the plumes, but the researchers estimated the mass of ice from the observed brightness of the plumes (because ice reflects light, so the more ice, the brighter the plumes). They deduced the mass of water vapor from a measurement of the molecular signature of vapor in the wavelengths of light Cassini observed from the plumes.

The scientists found that there were almost equal amounts of ice and water vapor. If this is the case, the researchers argued, the plumes cannot result from the sublimation of ice. The ice crystals are believed to be re-condensed from the vapor, rather than directly ejected from the surface or subsurface of the moon. A lot of vapor is needed to produce that 50/50 ice and vapor ratio, but the laws of thermodynamics prevent that much vapor from being produced solely by sublimation. Therefore, some of the vapor must be produced by evaporation rather than sublimation. This means a vast reserve of liquid water must exist on Enceladus, perhaps as shallow as 23 feet (7 m) under the surface. Under this theory, the researchers dubbed Enceladus' plumes "Cold Faithful" after the Old Faithful geyser in Yellowstone National Park. Their paper was published in 2006 in the journal Science.

But a new study led by Susan Kieffer of the University of Illinois at Urbana-Champaign challenges that work. She and her colleagues recalculated the ice-to-vapor ratio and produced vastly different results. Under their calculations, vapor is much more abundant than ice, with their final ratio less than 2:10, compared to the previous team's estimate of 1:1.

"We simply redid the calculations described in the [previous] paper and found that we could not reproduce the results quoted for either the abundance of vapor or the abundance of ice," Kieffer said. "Our conclusion was that sublimation should not have been excluded from consideration as a process that could produce the measured quantities, and thus should be considered as thoroughly as the liquid water hypothesis. Unfortunately, it has not been."

Kieffer and team published their findings in the May 2009 issue of the journal Icarus.

Conflicting interpretations

The two contradicting conclusions paint a vastly different picture of Enceladus. Under the first, the moon has an icy veneer that masks a dynamic region of flowing water under the surface that could possibly host life. But another interpretation sees Enceladus as a frigid world, solid with ice and rock all the way through.

"Water is certainly present in Enceladus, at least as solid and vapor, but the presence of vapor does not necessarily imply that liquid water is present," Kieffer wrote with Brucke Jakosky, a scientist at the University of Colorado in Boulder, in an essay in the June 13, 2008 issue of Science. "A definitive answer about the potential for life may have to await a follow-on spacecraft mission that can make specific high-resolution observations that could distinguish between the competing models."

The authors of the original paper, with the more hopeful outlook on the possibility of liquid water on the moon, agree that more work is needed to solve the conundrum and understand the conflicting estimates of the plumes' ice-to-vapor ratio.

"Serious analysis of the Enceladus plume images are only just beginning on the imaging team, and the jury is still very much out on this subject," Porco said in response to the new paper.

Andrew Ingersoll, a planetary scientist at Caltech, was involved with the original Porco et al. estimate, but said he doesn't believe that either ratio is truly accurate.

"Right now, I am not convinced by anyone's estimates of the ice/vapor ratio," he said. Ingersoll is currently working on a new, revised estimate.

Cassini is also scheduled to make future flybys of the moon, which could help refine the estimates.

"There are a number of reasons that the ice/vapor ratio cannot be used to prove or disprove either model," Kieffer said. "Nevertheless, it was the ice/vapor ratio from the original paper that gave the liquid water hypothesis its momentum. The point of our Icarus paper is that this value was miscalculated, that two competing hypotheses should have been set in motion, and both should still be considered by the scientific community."

The intriguing possibilities and conflicting interpretations of Enceladus are reasons why many scientists are pushing for a dedicated spacecraft mission to the moon. Though no official plans exist, a number of proposals are currently being considered for future NASA and ESA (European Space Agency) missions."<

posted in Astronomy - 1 reply

Saturn's has a very large ring

idea1407 — Wed, 07 Oct 2009 15:06:22 GMT

http://www.space.com/scienceastronomy/091007-saturn-big-ring.html

>"Enormous New Ring Found Distantly Orbiting Saturn
By Andrea Thompson
Senior Writer
posted: 07 October 2009
09:32 am ET

There's a new king of rings in the solar system: An enormous new ring has been discovered around Saturn, made up of debris from the gas giant's distant moon Phoebe.

Before the discovery of this massive ring — about 12.5 times the average distance between the Earth and the moon in width and 6 times that distance in thickness — the largest known planetary rings were Jupiter's gossamer rings and Saturn's E ring.

Astronomers have long suspected the presence of this ring, which orbits Saturn at a radius of about 8 million miles (13 million km) — 200 times the radius of the planet itself.

"There were hints that it could be there," said Douglas Hamilton of the University of Maryland, one of the astronomers who found the ring.

One such hint was the unusual coloring of Saturn's moon Iapetus, which had one dark side and one light side. Some astronomers suspected that the dark side, which looked suspiciously similar in composition to another of Saturn's satellite, Phoebe, was actually debris dust from Phoebe stuck to Iapetus' surface.

But astronomers haven't been able to detect it until now because, "this thing is just immense," Hamilton told SPACE.com. "If you look at just a small patch of it, you just see fuzziness."

Hamilton and his colleagues were finally able to see the behemoth ring with the infrared capability of the Spitzer Space Telescope. Spitzer was able to detect the sunlight reflected by the tiny dark black particles. The discovery is detailed in the Oct. 8 issue of the journal Nature.

The particles were likely created when asteroids, meteors or other bodies collided with Phoebe over the eons. While some of the particles are small enough to drift out of Saturn's gravitational grasp and into interplanetary space, others drift inwards toward the planet, where some get stuck to the leading hemisphere of Iapetus, which trawls through them. Periodic collisions replace the particles lost in these ways.

Interestingly, Phoebe and its associated dust ring travel in the opposite direction of Saturn's other rings and satellites.

The tiny particles are extremely diffuse, with only about 20 in every cubic kilometer of the ring, Hamilton said.

"If you were there, you wouldn't know you were in a ring," he said.

And because the other gas giants are known to have far-out, irregular satellites like Phoebe, it is likely that they also have similarly large, diffuse rings orbiting millions of kilometers out.

"I think this is the tip of the iceberg," Hamilton said."<

posted in Astronomy - 2 replies

Lunar Impact

Serge — Wed, 07 Oct 2009 04:21:37 GMT

Space Weather News for Oct. 6, 2009
http://spaceweather.com

This Friday morning, Oct 9th, at approximately 4:30 am PDT, NASA's LCROSS spacecraft and its Centaur booster rocket will plunge one after another into a shadowed crater near the Moon's south pole. The spectacular double-impact will be shown live on NASA TV from the point of view of the LCROSS spacecraft. Meanwhile, impact debris plumes emerging from the crater may be visible through backyard telescopes. North American sky watchers west of the Mississippi river are favored with darkness and good views of the Moon at the time of impact. Visit http://spaceweather.com for observing tips and full coverage.

posted in Astronomy - 15 replies

The Purpose of the Moon?

in-PHI-net — Fri, 02 Oct 2009 03:40:30 GMT

I am very curious about the moon. It amazes me that our moon takes so many hits and blasts from meteoroids and asteroids, but Earth is somewhat shielded and safe. Is there something in the moon (illuminated rocks/magnetic field?) that attracts these flying objects to itself, which in turn protects Earth? Is the moon a naturall guard against space debris for this planet? I understand that Jupiter protects us to some degree.

What is the purpose of the Moon?

posted in Astronomy - 22 replies

Proto-planet by Hubble

idea1407 — Thu, 08 Oct 2009 19:15:27 GMT

http://dsc.discovery.com/space/big-pic/hubble-pallas-asteroid-protoplanet.html

>"Oct. 8, 2009 -- A protoplanet is a planetary embryo, a baby planet undergoing accretion by smaller pieces of space rock in protoplanetary disks. Although the Solar System's bodies are fully evolved planets, dwarf planets and asteroids, there is a very exclusive group of large asteroids with a protoplanetary flavor.

This exclusive group just added another member.

In research using the Hubble Space Telescope, a team headed by UCLA scientists have deduced that an asteroid measuring 265 km (165 miles) in diameter is a protoplanet, joining asteroids 1 Ceres and 4 Vesta as only the third intact protoplanet. 2 Pallas is one of the largest asteroids in the asteroid belt (orbiting the sun at a distance of between 3.4 AU and 2.1 AU), accounting for 7 percent of the total mass of the entire belt.

This new 2 Pallas study (to be published in the Oct. 9 issue of Science) identified color variations and features in the asteroid's surface that can be linked to the asteroid's thermal evolution, indicating that this planetary embryo had the potential to grow. The researchers proposed that 2 Pallas formed from water-rich material and that internal alteration (i.e. the differentiation of elements common in the interior of planets) may have occurred.

In addition, analysis of an impact crater on the asteroid has indicated that 2 Pallas was hit by something large in the past, generating lots of debris. It is thought that this impact may have produced what are known as "Pallas family" objects that continue to orbit with the asteroid to this day."<

Click on link for pic

posted in Astronomy - 0 replies

Top Ten Lunar Impacts

Hummingbird — Thu, 08 Oct 2009 13:34:49 GMT

http://www.space.com/scienceastronomy/080320-top10-mooncrashes.html

Ten natural and human caused impacts.

posted in Astronomy - 1 reply

NASA Refines Asteroid Apophis' Path Toward Earth

Serge — Wed, 07 Oct 2009 22:05:49 GMT

DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

News release: 2009-151, Oct. 7, 2009

PASADENA, Calif. -- Using updated information, NASA scientists have recalculated the path of a large asteroid. The refined path indicates a significantly reduced likelihood of a hazardous encounter with Earth in 2036.

The Apophis asteroid is approximately the size of two-and-a-half football fields. The new data were documented by near-Earth object scientists Steve Chesley and Paul Chodas at NASA's Jet Propulsion Laboratory in Pasadena, Calif. They will present their updated findings at a meeting of the American Astronomical Society's Division for Planetary Sciences in Puerto Rico on Oct. 8.

"Apophis has been one of those celestial bodies that has captured the public's interest since it was discovered in 2004," said Chesley. "Updated computational techniques and newly available data indicate the probability of an Earth encounter on April 13, 2036, for Apophis has dropped from one-in-45,000 to about four-in-a million."

A majority of the data that enabled the updated orbit of Apophis came from observations Dave Tholen and collaborators at the University of Hawaii's Institute for Astronomy in Manoa made. Tholen pored over hundreds of previously unreleased images of the night sky made with the University of Hawaii's 2.2-meter (88-inch) telescope, located near the summit of Mauna Kea.

Tholen made improved measurements of the asteroid's position in the images, enabling him to provide Chesley and Chodas with new data sets more precise than previous measures for Apophis. Measurements from the Steward Observatory's 2.3 meter (90-inch) Bok telescope on Kitt Peak in Arizona and the Arecibo Observatory on the island of Puerto Rico also were used in Chesley's calculations.

The information provided a more accurate glimpse of Apophis' orbit well into the latter part of this century. Among the findings is another close encounter by the asteroid with Earth in 2068 with chance of impact currently at approximately three-in-a-million. As with earlier orbital estimates where Earth impacts in 2029 and 2036 could not initially be ruled out due to the need for additional data, it is expected that the 2068 encounter will diminish in probability as more information about Apophis is acquired.

Initially, Apophis was thought to have a 2.7 percent chance of impacting Earth in 2029. Additional observations of the asteriod ruled out any possibility of an impact in 2029. However, the asteroid is expected to make a record-setting -- but harmless -- close approach to Earth on Friday, April 13, 2029, when it comes no closer than 29,450 kilometers (18,300 miles) above Earth's surface.

"The refined orbital determination further reinforces that Apophis is an asteroid we can look to as an opportunity for exciting science and not something that should be feared," said Don Yeomans, manager of the Near-Earth Object Program Office at JPL. "The public can follow along as we continue to study Apophis and other near-Earth objects by visiting us on our AsteroidWatch Web site and by following us on the @AsteroidWatch Twitter feed."

The science of predicting asteroid orbits is based on a physical model of the solar system which includes the gravitational influence of the sun, moon, other planets and the three largest asteroids.

NASA detects and tracks asteroids and comets passing close to Earth using both ground and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them and plots their orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Cornell University, Ithaca, N.Y., operates the Arecibo Observatory under a cooperative agreement with the National Science Foundation in Arlington, Va.

For more information about asteroids and near-Earth objects, visit:

http://www.jpl.nasa.gov/asteroidwatch

For more information about NASA, visit: http://www.nasa.gov

- end -

posted in Astronomy - 1 reply

NASA Space Telescope Discovers Largest Ring Around Saturn

Serge — Wed, 07 Oct 2009 04:22:57 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

J.D. Harrington 202-358-5241
NASA Headquarters, Washington
j.d.harrington@nasa.gov

News release: 2009-150, Oct. 6, 2009

PASADENA, Calif. -- NASA's Spitzer Space Telescope has discovered an enormous ring around Saturn -- by far the largest of the giant planet's many rings.

The new belt lies at the far reaches of the Saturnian system, with an orbit tilted 27 degrees from the main ring plane. The bulk of its material starts about six million kilometers (3.7 million miles) away from the planet and extends outward roughly another 12 million kilometers (7.4 million miles). One of Saturn's farthest moons, Phoebe, circles within the newfound ring, and is likely the source of its material.

Saturn's newest halo is thick, too -- its vertical height is about 20 times the diameter of the planet. It would take about one billion Earths stacked together to fill the ring.

"This is one supersized ring," said Anne Verbiscer, an astronomer at the University of Virginia, Charlottesville. "If you could see the ring, it would span the width of two full moons' worth of sky, one on either side of Saturn." Verbiscer; Douglas Hamilton of the University of Maryland, College Park; and Michael Skrutskie, of the University of Virginia, Charlottesville, are authors of a paper about the discovery to be published online tomorrow by the journal Nature.

An artist's concept of the newfound ring is online at http://www.nasa.gov/mission_pages/spitzer/multimedia/spitzer-20091007a.html .

The ring itself is tenuous, made up of a thin array of ice and dust particles. Spitzer's infrared eyes were able to spot the glow of the band's cool dust. The telescope, launched in 2003, is currently 107 million kilometers (66 million miles) from Earth in orbit around the sun.

The discovery may help solve an age-old riddle of one of Saturn's moons. Iapetus has a strange appearance -- one side is bright and the other is really dark, in a pattern that resembles the yin-yang symbol. The astronomer Giovanni Cassini first spotted the moon in 1671, and years later figured out it has a dark side, now named Cassini Regio in his honor. A stunning picture of Iapetus taken by NASA's Cassini spacecraft is online at http://photojournal.jpl.nasa.gov/catalog/PIA08384 .

Saturn's newest addition could explain how Cassini Regio came to be. The ring is circling in the same direction as Phoebe, while Iapetus, the other rings and most of Saturn's moons are all going the opposite way. According to the scientists, some of the dark and dusty material from the outer ring moves inward toward Iapetus, slamming the icy moon like bugs on a windshield.

"Astronomers have long suspected that there is a connection between Saturn's outer moon Phoebe and the dark material on Iapetus," said Hamilton. "This new ring provides convincing evidence of that relationship."

Verbiscer and her colleagues used Spitzer's longer-wavelength infrared camera, called the multiband imaging photometer, to scan through a patch of sky far from Saturn and a bit inside Phoebe's orbit. The astronomers had a hunch that Phoebe might be circling around in a belt of dust kicked up from its minor collisions with comets -- a process similar to that around stars with dusty disks of planetary debris. Sure enough, when the scientists took a first look at their Spitzer data, a band of dust jumped out.

The ring would be difficult to see with visible-light telescopes. Its particles are diffuse and may even extend beyond the bulk of the ring material all the way in to Saturn and all the way out to interplanetary space. The relatively small numbers of particles in the ring wouldn't reflect much visible light, especially out at Saturn where sunlight is weak.

"The particles are so far apart that if you were to stand in the ring, you wouldn't even know it," said Verbiscer.

Spitzer was able to sense the glow of the cool dust, which is only about 80 Kelvin (minus 316 degrees Fahrenheit). Cool objects shine with infrared, or thermal radiation; for example, even a cup of ice cream is blazing with infrared light. "By focusing on the glow of the ring's cool dust, Spitzer made it easy to find," said Verbiscer.

These observations were made before Spitzer ran out of coolant in May and began its "warm" mission.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA. The multiband imaging photometer for Spitzer was built by Ball Aerospace Corporation, Boulder, Colo., and the University of Arizona, Tucson. Its principal investigator is George Rieke of the University of Arizona.

For additional images relating to the ring discovery and more information about Spitzer, visit http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer .

- end -

posted in Astronomy - 0 replies

Globular Cluster Question

Freakshowcrow — Mon, 05 Oct 2009 15:49:53 GMT

Why are the majority of the stars in globular clusters really, really, really old?

Over 10 billion years old. Plus if they are that ancient why are they still "shining" (after accounting for distance in space = distance in the past of course.) today?

posted in Astronomy - 3 replies

Calling All Space Buffs!

Serge — Sat, 03 Oct 2009 19:26:13 GMT

Calling All Space Buffs!

Do you love space? Are you good about sharing your love of the stars with the public? If so, here's a chance to join a growing network of space enthusiasts who have volunteered as NASA Solar System Ambassadors.
Ambassadors are especially needed to represent Delaware and North Dakota.

The application period is being extended through Oct. 16. Ambassadors are U.S. citizens selected from all 50 states, plus Washington, D.C., and Puerto Rico, or U.S. citizens serving U.S. audiences abroad.
The program is one of the longest-running NASA volunteer outreach projects.

Each ambassador receives online training from JPL, and educational materials supplied by various space missions,
such as the next Mars rover--Curiosity. Curiosity will check to see whether Mars has been favorable for supporting microbial life and preserving evidence of life. The rover is scheduled to launch in October 2011.

You can apply to be a NASA Solar System Ambassador at: http://www.jpl.nasa.gov/events/ssa.cfm .

For more information on JPL's Solar System Ambassador Program, visit http://www2.jpl.nasa.gov/ambassador/index.html , or contact Kay Ferrari at ambassadors@jpl.nasa.gov or at 818-354-7581.

A calendar of events hosted by ambassadors is available at http://www2.jpl.nasa.gov/ambassador/events.html .

JPL is managed for NASA by the California Institute of Technology in Pasadena, Calif.

-end-

From: subscription email

posted in Astronomy - 0 replies

Mercury's Bright Spot

idea1407 — Thu, 01 Oct 2009 18:14:48 GMT

http://www.space.com/scienceastronomy/091001-mercury-bright-spot.html

>"Mercury's Mysterious Bright Spot Photographed Up Close
By Andrea Thompson
Senior Writer
posted: 01 October 2009
12:23 pm ET

During its most recent flyby of Mercury, NASA's MESSENGER spacecraft caught another glimpse of the innermost planet's mysterious bright spot.

The MESSENGER probe skimmed just 142 miles (228 km) above Mercury at its closest approach as it whipped around the planet during the flyby, the last of three designed to guide the spacecraft into orbit around the planet in 2011.

The $446 million probe snapped several new images of Mercury during the flyby, despite a minor data hiccup that delayed the downlink of some of the images.

One of the new images shows a bright spot on the planet's surface, a feature that scientists cannot yet explain.

The new view was the third of the spot, which was first seen in telescopic images of Mercury obtained from Earth by astronomer Ronald Dantowitz. The second view was obtained by the MESSENGER Narrow Angle Camera during the spacecraft's second Mercury flyby Oct. 6, 2008. At that time, the bright feature was just on the planet's limb (edge) as seen from MESSENGER.

Surprisingly, at the center of the bright halo is an irregular depression, which may have formed through volcanic processes. The object will be further investigated when MESSENGER arrives at its final orbit around Mercury.

In the new images were also pictures of impact basins, including a double-ring impact basin, with another large impact crater on its south-southwestern side. Double-ring basins are formed when a large meteoroid strikes the surface of a rocky planet.

The floor within the inner or peak ring appears to be smoother than the floor between the peak ring and the outer rim, possibly the result of lava flows that partially flooded the basin some time after impact.

Some of these craters are relatively fresh, formed by more recent impacts. On Mercury, like the Earth's moon, even ancient impact craters can be preserved on the surface because there is no atmosphere to cause erosion and no plate tectonics to recycle the rock, as there are on Earth.

One set of impact craters even coincidentally resemble a paw print.

MESSENGER was also able to image some of the same terrain as it did in its second flyby, but this time with slightly different lightning conditions. Different angles of sunlight can better show the topography of the planet's surface.

MESSENGER made its closest approach to Mercury at about 5:55 p.m. EDT (2155 GMT) when it sped by at about 12,000 mph (19,312 kph). The probe then flew behind Mercury, passing out of communications with Earth for about an hour before restoring contact.

The spacecraft is the first probe to visit Mercury since NASA's Mariner 10 mission in the mid-1970s.

NASA launched MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging - in 2004. The probe swung past Earth once and Venus twice before beginning its three Mercury flybys."<

posted in Astronomy - 0 replies

Star formation and magnetism

idea1407 — Wed, 30 Sep 2009 14:36:22 GMT

http://www.space.com/scienceastronomy/090929-star-formation.html

>"Magnetic Fields Guide Star Birth

By SPACE.com Staff

posted: 29 September 2009
08:52 am ET

The picture of star formation just got a little more complicated: Cosmic magnetic fields, which can channel condensing interstellar gas, play a more important role in the birth of stars that previously thought, a new study suggests.

The simplified story of stellar birth involves giant clouds of gas and dust collapsing inward due to gravity, growing denser and hotter until nuclear fusion ignites a newborn star.

But in reality, there's much more to the story: When a molecular cloud collapses, only a small fraction of the cloud's material forms stars, and scientists haven't been sure why that is.

Since gravity favors star formation because it draws material together, some other force must be hindering the process, scientists reason. The two leading candidates are turbulence and magnetic fields.

Magnetic fields (produced by moving electrical charges and present around stars and most planets, including Earth) channel flowing gas, making it hard to draw the gas in from all directions. Turbulence stirs the gas and induces and outward pressure that counteracts gravity.

"The relative importance of magnetic fields versus turbulence is a matter of much debate," said astronomer Hua-bai Li of the Harvard-Smithsonian Center for Astrophysics. "Our findings serve as the first observational constraint on this issue."

Li and his team studied 25 dense patches, or cloud cores, each one about a light-year in size. The cores, which act as seeds from which stars form, were located within molecular clouds as much as 6,500 light-years from Earth. (A light-year is the distance light travels in a year, or 6 trillion miles.)

The researchers studied polarized light, which has electric and magnetic components that are aligned in specific directions. From the polarization, they measured the magnetic fields within each cloud core and compared them to the fields in the surrounding, tenuous nebula.

The magnetic fields tended to line up in the same direction, even though the relative size scales (1 light-year cores versus 1,000 light-year nebulas) and densities were different by orders of magnitude. Since turbulence would tend to churn the nebula and mix up magnetic field directions, their findings show that magnetic fields dominate turbulence in influencing star birth.

"Our result shows that molecular cloud cores located near each other are connected not only by gravity but also by magnetic fields," Li said. "This shows that computer simulations modeling star formation must take strong magnetic fields into account."

The study will be detailed in an upcoming issue of the Astrophysical Journal."<

posted in Astronomy - 5 replies

How we know what the objects in the universe are made of.

Serge — Tue, 29 Sep 2009 20:55:21 GMT

Generally, the light we see is composed of a mixture of wavelengths. White light is composed of red, green, yellow, and blue photons. We can separate light into its component wavelengths by using a dispersing element, either a prism or a diffraction grating. Once the light is dispersed, it forms a spectrum. A rainbow is an example of a spectrum (the dispersing elements are water droplets which act as prisms). The plural of "spectrum" is "spectra".

There are 2 basic kinds of spectra:

Continuous spectra, like a rainbow.
Line spectra. The light is concentrated into specific colors or wavelengths.

Spectra are a powerful tool for studying astronomical objects.

A diffraction grating consists usually of thousands of narrow, closely spaced parallel slits (or grooves). These grooves selectively filter the light, spreading it into patches of specific wavelengths, so that the resulting image beyond the grating contains the color bars representing the signature pattern of the source of light. Elements which are gaseous can be identified by shining a light through them. As long as the light source has a continuous spectrum, and the gas is cooler than the source, then the image created by the diffraction grating identifies the gas by its absorption lines.

Elements that are liquid or solid can be identified by examining the reflected light from a source with a continuous spectrum...

Continue - http://hea-www.harvard.edu/~efortin/thesis/html/Spectroscopy.shtml ; with awesome visualisations.

posted in Astronomy - 1 reply

Radar Map of Buried Mars Layers Matches Climate Cycles

Serge — Sun, 27 Sep 2009 23:39:26 GMT

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Maria Martinez 210-522-3305
Southwest Research Institute, San Antonio, Texas
maria.martinez@swri.org

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

News release: 2009-144, September 22, 2009

PASADENA, Calif. -- New, three-dimensional imaging of Martian north-polar ice layers by a radar instrument on NASA's Mars Reconnaissance Orbiter is consistent with theoretical models of Martian climate swings during the past few million years.

Alignment of the layering patterns with the modeled climate cycles provides insight about how the layers accumulated. These ice-rich, layered deposits cover an area one-third larger than Texas and form a stack up to 2 kilometers (1.2 miles) thick atop a basal deposit with additional ice.

"Contrast in electrical properties between layers is what provides the reflectivity we observe with the radar," said Nathaniel Putzig of Southwest Research Institute, Boulder, Colo., a member of the science team for the Shallow Radar instrument on the orbiter. "The pattern of reflectivity tells us about the pattern of material variations within the layers."

Earlier radar observations indicated that the Martian north-polar layered deposits are mostly ice. Radar contrasts between different layers in the deposits are interpreted as differences in the concentration of rock material, in the form of dust, mixed with the ice. These deposits on Mars hold about one-third as much water as Earth's Greenland ice sheet.

Putzig and nine co-authors report findings from 358 radar observations in a paper accepted for publication by the journal Icarus and currently available online.

Their radar results provide a cross-sectional view of the north-polar layered deposits of Mars, showing that high-reflectivity zones, with multiple contrasting layers, alternate with more-homogenous zones of lower reflectivity. Patterns of how these two types of zones alternate can be correlated to models of how changes in Mars' tilt on its axis have produced changes in the planet's climate in the past 4 million years or so, but only if some possibilities for how the layers form are ruled out.

"We're not doing the climate modeling here; we are comparing others' modeling results to what we observe with the radar, and using that comparison to constrain the possible explanations for how the layers form," Putzig said.

The most recent 300,000 years of Martian history are a period of less dramatic swings in the planet's tilt than during the preceding 600,000 years. Since the top zone of the north-polar layered deposits -- the most recently deposited portion -- is strongly radar-reflective, the researchers propose that such sections of high-contrast layering correspond to periods of relatively small swings in the planet's tilt.

They also propose a mechanism for how those contrasting layers would form. The observed pattern does not fit well with an earlier interpretation that the dustier layers in those zones are formed during high-tilt periods when sunshine on the polar region sublimates some of the top layer's ice and concentrates the dust left behind. Rather, it fits an alternative interpretation that the dustier layers are simply deposited during periods when the atmosphere is dustier.

The new radar mapping of the extent and depth of five stacked units in the north-polar layered deposits reveals that the geographical center of ice deposition probably shifted by 400 kilometers (250 miles) or more at least once during the past few million years.

"The radar has been giving us spectacular results," said Jeffrey Plaut of NASA's Jet Propulsion Laboratory, Pasadena, Calif., a co-author of the paper. "We have mapped continuous underground layers in three dimensions across a vast area."

The Italian Space Agency operates the Shallow Radar instrument, which it provided for NASA's Mars Reconnaissance Orbiter. The orbiter has been studying Mars with six advanced instruments since 2006. It has returned more data from the planet than all other past and current missions to Mars combined. For more information about the mission, visit: http://www.nasa.gov/mro .

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

- end -

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posted in Astronomy - 11 replies

Mars: meterorites expose water after impact

idea1407 — Sat, 26 Sep 2009 19:40:58 GMT

http://www.youtube.com/watch?v=B7cmPU2NLJ4

posted in Astronomy - 0 replies

Water molecules on Moon

idea1407 — Thu, 24 Sep 2009 19:35:24 GMT

http://www.nasa.gov/home/hqnews/2009/sep/HQ_09-222_Moon_Water_Molecules.html

>"RELEASE : 09-222

NASA Instruments Reveal Water Molecules on Lunar Surface

WASHINGTON -- NASA scientists have discovered water molecules in the polar regions of the moon. Instruments aboard three separate spacecraft revealed water molecules in amounts that are greater than predicted, but still relatively small. Hydroxyl, a molecule consisting of one oxygen atom and one hydrogen atom, also was found in the lunar soil. The findings were published in Thursday's edition of the journal Science.

NASA's Moon Mineralogy Mapper, or M3, instrument reported the observations. M3 was carried into space on Oct. 22, 2008, aboard the Indian Space Research Organization's Chandrayaan-1 spacecraft. Data from the Visual and Infrared Mapping Spectrometer, or VIMS, on NASA's Cassini spacecraft and the High-Resolution Infrared Imaging Spectrometer on NASA's EPOXI spacecraft contributed to confirmation of the finding. The spacecraft imaging spectrometers made it possible to map lunar water more effectively than ever before.

The confirmation of elevated water molecules and hydroxyl at these concentrations in the moon's polar regions raises new questions about its origin and effect on the mineralogy of the moon. Answers to these questions will be studied and debated for years to come.

"Water ice on the moon has been something of a holy grail for lunar scientists for a very long time," said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington. "This surprising finding has come about through the ingenuity, perseverance and international cooperation between NASA and the India Space Research Organization."

From its perch in lunar orbit, M3's state-of-the-art spectrometer measured light reflecting off the moon's surface at infrared wavelengths, splitting the spectral colors of the lunar surface into small enough bits to reveal a new level of detail in surface composition. When the M3 science team analyzed data from the instrument, they found the wavelengths of light being absorbed were consistent with the absorption patterns for water molecules and hydroxyl.

"For silicate bodies, such features are typically attributed to water and hydroxyl-bearing materials," said Carle Pieters, M3's principal investigator from Brown University. "When we say 'water on the moon,' we are not talking about lakes, oceans or even puddles. Water on the moon means molecules of water and hydroxyl that interact with molecules of rock and dust specifically in the top millimeters of the moon's surface. "

The M3 team found water molecules and hydroxyl at diverse areas of the sunlit region of the moon's surface, but the water signature appeared stronger at the moon's higher latitudes. Water molecules and hydroxyl previously were suspected in data from a Cassini flyby of the moon in 1999, but the findings were not published until now.

"The data from Cassini's VIMS instrument and M3 closely agree," said Roger Clark, a U.S. Geological Survey scientist in Denver and member of both the VIMS and M3 teams. "We see both water and hydroxyl. While the abundances are not precisely known, as much as 1,000 water molecule parts-per-million could be in the lunar soil. To put that into perspective, if you harvested one ton of the top layer of the moon's surface, you could get as much as 32 ounces of water."

For additional confirmation, scientists turned to the EPOXI mission while it was flying past the moon in June 2009 on its way to a November 2010 encounter with comet Hartley 2. The spacecraft not only confirmed the VIMS and M3 findings, but also expanded on them.

"With our extended spectral range and views over the north pole, we were able to explore the distribution of both water and hydroxyl as a function of temperature, latitude, composition, and time of day," said Jessica Sunshine of the University of Maryland. Sunshine is EPOXI's deputy principal investigator and a scientist on the M3 team. "Our analysis unequivocally confirms the presence of these molecules on the moon's surface and reveals that the entire surface appears to be hydrated during at least some portion of the lunar day."

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the M3 instrument, Cassini mission and EPOXI spacecraft for NASA's Science Mission Directorate in Washington. The Indian Space Research Organization built, launched and operated the Chandrayaan-1 spacecraft."<

posted in Astronomy - 2 replies

NASA's Spitzer Spots Clump of Swirling Planetary Material

Serge — Thu, 24 Sep 2009 22:38:53 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

News release: 2009-146, Sept. 23, 2009

PASADENA, Calif. -- Astronomers have witnessed odd behavior around a young star. Something, perhaps another star or a planet, appears to be pushing a clump of planet-forming material around. The observations, made with NASA's Spitzer Space Telescope, offer a rare look into the early stages of planet formation.

Planets form out of swirling disks of gas and dust. Spitzer observed infrared light coming from one such disk around a young star, called LRLL 31, over a period of five months. To the astronomers' surprise, the light varied in unexpected ways, and in as little time as one week. Planets take millions of years to form, so it's rare to see anything change on time scales we humans can perceive.

One possible explanation is that a close companion to the star -- either a star or a developing planet -- could be shoving planet-forming material together, causing its thickness to vary as it spins around the star.

"We don't know if planets have formed, or will form, but we are gaining a better understanding of the properties and dynamics of the fine dust that could either become, or indirectly shape, a planet," said James Muzerolle of the Space Telescope Science Institute, Baltimore, Md. Muzerolle is first author of a paper accepted for publication in the Astrophysical Journal Letters. "This is a unique, real-time glimpse into the lengthy process of building planets."

One theory of planet formation suggests that planets start out as dusty grains swirling around a star in a disk. They slowly bulk up in size, collecting more and more mass like sticky snow. As the planets get bigger and bigger, they carve out gaps in the dust, until a so-called transitional disk takes shape with a large doughnut-like hole at its center. Over time, this disk fades and a new type of disk emerges, made up of debris from collisions between planets, asteroids and comets. Ultimately, a more settled, mature solar system like our own forms.

Before Spitzer was launched in 2003, only a few transitional disks with gaps or holes were known. With Spitzer's improved infrared vision, dozens have now been found. The space telescope sensed the warm glow of the disks and indirectly mapped out their structures.

Muzerolle and his team set out to study a family of young stars, many with known transitional disks. The stars are about two to three million years old and about 1,000 light-years away, in the IC 348 star-forming region of the constellation Perseus. A few of the stars showed surprising hints of variations. The astronomers followed up on one, LRLL 31, studying the star over five months with all three of Spitzer's instruments.

The observations showed that light from the inner region of the star's disk changes every few weeks, and, in one instance, in only one week. "Transition disks are rare enough, so to see one with this type of variability is really exciting," said co-author Kevin Flaherty of the University of Arizona, Tucson.

Both the intensity and the wavelength of infrared light varied over time. For instance, when the amount of light seen at shorter wavelengths went up, the brightness at longer wavelengths went down, and vice versa.

Muzerolle and his team say that a companion to the star, circling in a gap in the system's disk, could explain the data. "A companion in the gap of an almost edge-on disk would periodically change the height of the inner disk rim as it circles around the star: a higher rim would emit more light at shorter wavelengths because it is larger and hot, but at the same time, the high rim would shadow the cool material of the outer disk, causing a decrease in the longer-wavelength light. A low rim would do the opposite. This is exactly what we observe in our data," said Elise Furlan, a co-author from NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The companion would have to be close in order to move the material around so fast -- about one-tenth the distance between Earth and the sun.

The astronomers plan to follow up with ground-based telescopes to see if a companion is tugging on the star hard enough to be perceived. Spitzer will also observe the system again in its "warm" mission to see if the changes are periodic, as would be expected with an orbiting companion. Spitzer ran out of coolant in May of this year, and is now operating at a slightly warmer temperature with two infrared channels still functioning.

"For astronomers, watching anything in real-time is exciting," said Muzerolle. "It's like we're biologists getting to watch cells grow in a petri dish, only our specimen is light-years away."

Other authors are Zoltan Balog, Max Planck Institute for Astronomy, Germany; Paul S. Smith and George Rieke, University of Arizona; Lori Allen, National Optical Astronomy Observatory, Tucson; Nuria Calvet, University of Michigan, Ann Arbor; Paola D'Alessio, National Autonomous University of Mexico; S. Thomas Megeath, University of Toledo, Ohio; August Muench, Harvard-Smithsonian Center for Astrophysics, Cambridge; William H. Sherry, National Solar Observatory, Tucson.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena. Caltech manages JPL for NASA. For more information about Spitzer, visit http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer .

- end -

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posted in Astronomy - 1 reply

NASA Spacecraft Sees Ice on Mars Exposed by Meteor Impacts

Serge — Thu, 24 Sep 2009 22:33:30 GMT

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

News release: 2009-148, Sept. 24, 2009

PASADENA, Calif. -- NASA's Mars Reconnaissance Orbiter has revealed frozen water hiding just below the surface of mid-latitude Mars. The spacecraft's observations were obtained from orbit after meteorites excavated fresh craters on the Red Planet.

Scientists controlling instruments on the orbiter found bright ice exposed at five Martian sites with new craters that range in depth from approximately half a meter to 2.5 meters (1.5 feet to 8 feet). The craters did not exist in earlier images of the same sites. Some of the craters show a thin layer of bright ice atop darker underlying material. The bright patches darkened in the weeks following initial observations, as the freshly exposed ice vaporized into the thin Martian atmosphere. One of the new craters had a bright patch of material large enough for one of the orbiter's instruments to confirm it is water-ice.

The finds indicate water-ice occurs beneath Mars' surface halfway between the north pole and the equator, a lower latitude than expected in the Martian climate.

"This ice is a relic of a more humid climate from perhaps just several thousand years ago," said Shane Byrne of the University of Arizona, Tucson.

Byrne is a member of the team operating the orbiter's High Resolution Imaging Science Experiment, or HiRISE camera, which captured the unprecedented images. Byrne and 17 co-authors report the findings in the Sept. 25 edition of the journal Science.

"We now know we can use new impact sites as probes to look for ice in the shallow subsurface," said Megan Kennedy of Malin Space Science Systems in San Diego, a co-author of the paper and member of the team operating the orbiter's Context Camera.

During a typical week, the Context Camera returns more than 200 images of Mars that cover a total area greater than California. The camera team examines each image, sometimes finding dark spots that fresh, small craters make in terrain covered with dust. Checking earlier photos of the same areas can confirm a feature is new. The team has found more than 100 fresh impact sites, mostly closer to the equator than the ones that revealed ice.

An image from the camera on Aug. 10, 2008, showed apparent cratering that occurred after an image of the same ground was taken 67 days earlier. The opportunity to study such a fresh impact site prompted a look by the orbiter's higher resolution camera on Sept. 12, 2009, confirming a cluster of small craters.

"Something unusual jumped out," Byrne said. "We observed bright material at the bottoms of the craters with a very distinct color. It looked a lot like ice."

The bright material at that site did not cover enough area for a spectrometer instrument on the orbiter to determine its composition. However, a Sept. 18, 2008, image of a different mid-latitude site showed a crater that had not existed eight months earlier. This crater had a larger area of bright material.

"We were excited about it, so we did a quick-turnaround observation," said co-author Kim Seelos of Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "Everyone thought it was water-ice, but it was important to get the spectrum for confirmation."

Mars Reconnaissance Orbiter Project Scientist Rich Zurek, of NASA's Jet Propulsion Laboratory, Pasadena, Calif., said, "This mission is designed to facilitate coordination and quick response by the science teams. That makes it possible to detect and understand rapidly changing features."

The ice exposed by fresh impacts suggests that NASA's Viking Lander 2, digging into mid-latitude Mars in 1976, might have struck ice if it had dug 10 centimeters (4 inches) deeper. The Viking 2 mission, which consisted of an orbiter and a lander, launched in September 1975 and became one of the first two space probes to land successfully on the Martian surface. The Viking 1 and 2 landers characterized the structure and composition of the atmosphere and surface. They also conducted on-the-spot biological tests for life on another planet.

NASA's Jet Propulsion Laboratory in Pasadena manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft. The Context Camera was built and is operated by Malin Space Science Systems. The University of Arizona operates the HiRISE camera, which Ball Aerospace & Technologies Corp., in Boulder, Colo., built. The Johns Hopkins University Applied Physics Laboratory led the effort to build the Compact Reconnaissance Imaging Spectrometer and operates it in coordination with an international team of researchers.

To view images of the craters and learn more about the Mars Reconnaissance Orbiter, visit http://www.nasa.gov/mro or http://marsprogram.jpl.nasa.gov/mro/ .

- end -

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Teacher Training Opportunity: Goldstone Apple Valley Radio Telescope Program

Serge — Thu, 24 Sep 2009 03:11:02 GMT

The Lewis Center for Educational Research (LCER) announces an opportunity for K - 12 teachers to participate in our rather unique program. The Goldstone Apple Valley Radio Telescope Program (GAVRT) is an education partnership involving NASA, the Jet Propulsion Laboratory (JPL) and LCER. It is a K-12 project using radio astronomy to provide an opportunity for students to experience real science and to learn that science is an ongoing process and actual discovery is possible.
Using their classroom computer, 32,000 students have taken control of a 34-meter, 500-ton, 9-story-high radio telescope located at NASA's Deep Space Network at Goldstone, CA. We currently have trained 473 teachers at 283 schools in 37 states across the United States and at American schools in 14 countries and 3 U.S. territories.

What's in it for the kids? They learn how to gather data, understand what the data mean and how to follow through with analysis. Students and teachers team with scientists to conduct cutting-edge research leading to discovery. GAVRT excites students while accomplishing educational and scientific objectives.

We are excited to include Radio JOVE with our training in 2010. Radio JOVE is a NASA education program: Solar and planetary radio astronomy for schools. It is a hands-on educational activity that brings the radio sounds of the sun, Jupiter, the Milky Way galaxy and terrestrial radio noise to students, teachers and the general public. We target grade levels 6 - 14 to:

• Build a simple radio telescope kit
• Speak with professional radio astronomers
• Make scientific observations
• Interact with radio observatories in real-time

One of our main goals is to motivate students to learn about science by participating in a scientific activity, making measurements, acquiring and analyzing data, and sharing and discussing their results with other observers. For further information, see http://radiojove.gsfc.nasa.gov or call (301) 286-9790 or (615) 898-5946.

Teachers need to attend a 5-day class in order to take this program back to their students. Teachers interested in participating are invited to apply online at this time at http://www.lewiscenter.org/gavrt/opportunities.php. We are conducting a 5-day teacher training class at the Lewis Center on March 8 - 12, July 19 - 23, and October 25 - 29, 2010, at our facility in Apple Valley, CA. Please check our Web site periodically for calendar updates. We strongly recommend at least two teachers attend the training from your school, or area. While this is not a requirement, it will definitely serve to help in program support once back in the classroom. The cost of the 5-day class is $745. For questions, e-mail gavrt-info@lcer.org or call (760) 946-5414 X234.

More information about GAVRT can be found at http://www.lewiscenter.org/gavrt/ .

From: subscription email

posted in Astronomy - 1 reply

Saturn rings with mountains

idea1407 — Tue, 22 Sep 2009 08:44:42 GMT

http://www.space.com/scienceastronomy/090921-new-saturn-ring-images.html

>"Surprising, Huge Peaks Discovered in Saturn's Rings
By SPACE.com Staff

posted: 21 September 2009
06:49 pm ET

Stunning new views of Saturn from a NASA spacecraft have revealed odd formations in the planet's trademark rings, including ripples as tall as the Rocky Mountains.

The new images taken by NASA's Cassini spacecraft show that Saturn's icy rings - once thought to be relatively thin - can be miles thick in some points and include weird, bright streaks from clouds kicked up by the cosmic clash between ring particles and interloping space debris.

"It's like putting on 3-D glasses and seeing the third dimension for the first time," said Bob Pappalardo, Cassini's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a statement. "This is among the most important events Cassini has shown us."

Cassini recorded the new images of Saturn in the week surrounding the planet's Aug. 11 equinox, a time when its bright bands of rings are edge on to the sun and nearly invisible as seen from Earth.

The rare sight only occurs twice during Saturn's long orbit, which takes nearly 30 years to complete. Earth also has two equinoxes a year (vernal and autumnal), with the autumnal equinox to occur Tuesday.

Saturn's rings are made up of individual chunks of ice that reach out nearly 85,000 miles (140,000 km) from the center of the planet. In some spots they are only 30 feet (about 10 meters) thick, while others can reach towering heights, the new images revealed.

The unique lighting conditions brought on by Saturn's equinox and the sun illuminated the odd ripples and bumps among the planet's rings, which Cassini spied with its camera eyes. The staggering heights of some formations could be discerned by the shadows they cast, researchers said.

"We thought the plane of the rings was no taller than two stories of a modern-day building and instead we've come across walls more than 2 miles [3 kilometers] high," said Cassini imaging team leader Carolyn Porco at the Space Science Institute in Boulder, Colo. "Isn't that the most outrageous thing you could imagine? It truly is like something out of science fiction."

One ripple rises nearly 2 1/2 miles (4 km) above the plane of Saturn's rings. The big blip is caused by the gravitational tug of the planet's moon Daphnis. It is the highest peak among the rings, mission managers said.

Scientists estimate that there are about 35 trillion-trillion tons of ice, dust and rock locked up in Saturn's rings. Cassini has been studying Saturn and its rings since it arrived at the planet in 2004 and is currently in the middle of an extended mission to observe the gas giant's equinox period.

"To understand what we are seeing will take more time, but the images and data will help develop a more complete understanding of how old the rings might be and how they are evolving," said Linda Spilker, Cassini's deputy project scientist at JPL."<

posted in Astronomy - 0 replies

In Search of Dark Asteroids (and Other Sneaky Things)

Serge — Sat, 19 Sep 2009 01:42:27 GMT

Feature
September 18, 2009

Ninjas knew how to be stealthy: Be dark. Emit very little light. Move in the shadows between bright places.

In modern warfare, though, ninjas would be sitting ducks. Their black clothes may be hard to see at night with the naked eye, but their warm bodies would be clearly visible to a soldier wearing infrared goggles.

To hunt for the "ninjas" of the cosmos -- dim objects that lurk in the vast dark spaces between planets and stars -- scientists are building by far the most sensitive set of wide-angle infrared goggles ever, a space telescope called the Wide-field Infrared Survey Explorer, or WISE.

WISE will scan the entire sky at infrared wavelengths, creating the most comprehensive catalog yet of dark and dim objects in the cosmos: vast dust clouds, brown dwarf stars, asteroids -- even large, nearby asteroids that might pose a threat to Earth.

Surveys of nearby asteroids based on visible-light telescopes could be skewed toward asteroids with more-reflective surfaces. "If there's a significant population of asteroids nearby that are very dark, they will have been missed by these previous surveys," says Edward Wright, principal investigator for the mission and a physicist at UCLA.

The full-sky infrared map produced by WISE will reveal even these darker asteroids, mapping the locations and sizes of roughly 200,000 asteroids and giving scientists a clearer idea of how many large and potentially dangerous asteroids are nearby. WISE will also help answer questions about the formation of stars and the evolution and structure of galaxies, including our own Milky Way galaxy.

And the discoveries won't likely stop there.

"When you look at the sky with new sensitivity and a new wavelength band, like WISE is going to do, you're going to find new things that you didn't know were out there," Wright says.

Stars emit visible light in part because they're so hot. But cooler objects like asteroids emit light too, just at longer, infrared wavelengths that are invisible to the unaided eye. In fact, any object warmer than absolute zero will emit at least some infrared light.

Unfortunately, this fact makes building an infrared telescope rather difficult. Without a coolant, the telescope itself would glow in infrared light just like as other warm objects do. It would be like building a normal, visible-light telescope out of Times Square billboard lights: The telescope would be blinded by its own glow.

To solve this problem, WISE will cool its components to about 15 degrees Celsius above absolute zero (minus 258 degrees Celsius, or minus 433 degrees Fahrenheit) using a block of solid hydrogen. Mission scientists chose solid hydrogen over liquid helium, which is often used in research for cooling materials to near absolute zero, because a smaller volume of solid hydrogen can do the job. "The cooling power is much higher for hydrogen than for helium," Wright explains. When launching a telescope into space, being smaller and lighter saves money.

Previous space telescopes such as the Infrared Astronomical Satellite have mapped the sky at infrared wavelengths before, but WISE will be hundreds of times more sensitive. While other missions could only see diffuse sources of infrared light such as large dust clouds, WISE will be able to see asteroids and other point sources.

After it launches into orbit as early as this December, WISE will spend six months mapping the sky, during which it will download its data to ground stations four times each day. Analyzing that data should give scientists some new insights into the cosmos.

For example, one theory posits that most of the stars in the universe were formed in the press of colliding galaxies. When galaxies collide, interstellar clouds of gas and dust smash together, compressing the clouds and starting a self-perpetuating cycle of gravitational collapse. The result is a flurry of star birth. Newborn stars are usually concealed by the dusty clouds in which they are born. Ordinary light cannot escape, but infrared light can.

WISE will be able to detect infrared emissions from the most active star-forming regions. This will help scientists know how rapidly stars are formed during galactic collisions, which could indicate how many of the universe's stars were formed this way.

WISE will also target dim "failed stars" called brown dwarfs that outnumber ordinary stars by a wide margin. Mapping brown dwarfs in the Milky Way may reveal much about the structure and evolution of our own galaxy.

And this could be just the beginning of the discoveries scientists make once WISE puts the spotlight on stealthy denizens of the dark.

From material at Science@NASA

Media contact:
Whitney Clavin/ Jet Propulsion Laboratory
818-354-4673
whitney.clavin@jpl.nasa.gov

- end -

From: subscription email

posted in Astronomy - 3 replies

First Rocky World outside our solar system detected

idea1407 — Wed, 16 Sep 2009 15:28:40 GMT

http://www.space.com/scienceastronomy/090916-rocky-exoplanet.html

>"First Rocky World Confirmed Around Another Star
By Clara Moskowitz
Staff Writer
posted: 16 September 2009
08:43 am ET

One of the smallest exoplanets yet discovered has just been confirmed as a rocky world, scientists announced.

The planet, called CoRoT-7b, is the first planet beyond our solar system with a proven density similar to Earth's, astronomers say. Most known exoplanets are large gas giants like Jupiter.

"We have indications that other exoplanets could be rocky, but it's the first time that the density of such a planet has been measured," said study team member Claire Moutou of the Laboratoire d'Astrophysique de Marseille in France. "We are really sure it's rocky."

Though its terrestrial surface renders CoRoT-7b more similar to Earth than many other exoplanets are, it's still a far cry from a familiar setting. The planet orbits extremely close to its star – about 1.6 million miles (2.5 million km), or 23 times closer than Mercury is to the sun. At this range, the planet's surface temperatures are scorching, with highs above 2,000 degrees Fahrenheit (1,000 degrees Celsius) on the star-facing side.

CoRoT-7b's close proximity to its star means that the planet is likely to be tidally locked, with one side always facing its sun and the other side always in darkness.

"Probably the day side is very hot and is pure lava, boiling, and the other side probably is very cold, and it could be rocky with some mountains," Moutou told SPACE.com. "It's not possible that there is liquid water."

Crowded universe

CoRoT-7b was discovered in February 2009 by the CoRoT space telescope, a European collaboration. The tiny planet was discovered orbiting a star slightly smaller and cooler than our sun, about 500 light-years away. As the planet passed in front of its star, it eclipsed a small portion of the star's light, causing a dip in brightness.

This dip was enough to tell that a planet existed, and to estimate the planet's distance from its host star and its radius, which is about 80 percent larger than Earth's. But to learn its density, which would reveal whether it is a rocky or gas planet, requires a precise measurement of the parent star's velocity, which is slightly warped by the planet's small mass.

To make this measurement astronomers used the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph on the European Southern Observatory's 3.6-meter telescope at La Silla Observatory in Chile. The new data revealed that CoRoT-7b has a mass about five times that of Earth, making it one of the lightest exoplanets yet found.

With the planet's mass and radius, the researchers calculated its density (about 4.7 grams per cubic centimeter), which placed it in firm rocky territory.

"This is the first proof of the detection of a rocky planet," planet-formation theorist Alan Boss of the Carnegie Institution of Washington told SPACE.com.

"It shows that rocky planets really are commonplace," said Boss, who was not involved in the new research. "The estimates are that about 30 percent of sun-like stars have these hot and warm super-Earths, and now that we know the density of one of them, it is easy to make the claim that most of the rest of them are probably rocky too. The evidence is becoming overwhelming that we live in a crowded universe.""<

posted in Astronomy - 7 replies

Comet to many comets

idea1407 — Wed, 16 Sep 2009 17:14:00 GMT

http://www.space.com/scienceastronomy/090915-mini-comets.html

>"Comet Outburst Spawns Mini-Comets
By SPACE.com Staff

posted: 15 September 2009
08:43 pm ET

A comet recently spewed out a cluster of mini comets in a huge outburst that was the largest ever witnessed by astronomers.

A team of researchers began observing the comet 17P/Holmes in October 2007, after it was reported that the object, about 2.2 miles wide (3.6 km wide), had brightened by a million times in less than a day.

UCLA researcher Rachel Stevenson and colleagues noted multiple fragments flying rapidly away from the comet's nucleus. They continued observing for several weeks after the outburst using the Canada-France-Hawaii Telescope in Hawaii and watched as the dust cloud ejected by the comet grew to be larger than the sun.

The astronomers examined a sequence of images taken over nine nights using a digital filter that enhances small features. They found numerous tiny objects that moved away from the nucleus at speeds of up to 280 mph (125 meters per second). These objects were too bright to simply be bare rocks, but instead were more like mini comets, creating their own dust clouds as ice on their surfaces sublimated directly to vapor.

"Initially we thought this comet was unique simply because of the scale of the outburst," Stevenson said. "But we soon realized that the aftermath of the outburst showed unusual features, such as these fast-moving fragments, that have not been detected around other comets."

Although the outburst was impressive in the telescope images, it wasn't visible to the naked eye.

Scientists aren't sure of the exact cause of the outburst. Possibly, pressure inside the comet built up as it moved closer to the sun, until eventually part of the surface broke away, releasing a huge cloud of dust and gas, as well as larger fragments.

Even after ejecting mini comets, the solid nucleus of comet Holmes survived and continued on its orbit, seemingly unperturbed.

Holmes takes about 6 years to circle the sun, and travels between the inner edge of the asteroid belt to beyond Jupiter. The comet is now moving away from the sun but will return to its closest approach in 2014, when astronomers will examine it for signs of further outbursts.

Stevenson will present the findings at the European Planetary Science Congress in Potsdam, Germany on Wednesday."<

posted in Astronomy - 1 reply

New Ganymede map - so don't get lost

idea1407 — Wed, 16 Sep 2009 17:29:30 GMT

http://www.space.com/scienceastronomy/090915-ganymede-map.html

>"New Map Reveals Geology of Jupiter's Moon Ganymede
By SPACE.com Staff

posted: 15 September 2009
08:43 pm ET

Jupiter's moon Ganymede, the largest moon in the solar system, now has a detailed global map that will help scientists better understand the large, icy satellite.

The map is the product of a seven-year effort and is only the third global geological map ever compiled for a moon in the solar system, after Earth's moon and Jupiter's cratered satellite Callisto.

"The map really gives us a more complete understanding of the geological processes that have shaped the moon we see today," said Wes Patterson, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., who led the map effort.

Patterson's team will present the map, created with data images from NASA's historic Voyager and Galileo missions, on Wednesday at the 2009 European Planetary Science Congress in Potsdam, Germany.

With a diameter of 3,280 miles (5,262 km), Ganymede is the largest moon in the solar system. Larger than both planet Mercury and dwarf planet Pluto, it's also the only satellite in the solar system known to have its own magnetosphere.

While scientists have crafted several regional geological maps of Ganymede's surface using Voyager data, Patterson's team was the first to combine the low-resolution Voyager photos with high-resolution Galileo images to create a global and consistent view of the moon's geology.

The new map details geologic features that formed and evolved over much of our solar system's history. These features record evidence of the internal evolution of this large icy satellite, of its dynamical interactions with the other Galilean satellites, and of the evolution of the population of small bodies impacting the surface of the satellite.

"By mapping the entirety of Ganymede's surface, we can more accurately address scientific questions regarding the formation and evolution of this truly unique moon," Patterson said. "Work done using the map by collaborator Geoff Collins at Wheaton College, for instance, has shown that vast swaths of grooved terrain covering the surface of the satellite formed in a specific sequence. The details of this sequence tell us something about the forces that must have been necessary to form those swaths."

Patterson says scientists can look at Ganymede's geological history as a "touchstone" for comparing and contrasting the characteristics and evolution of other large to mid-sized icy satellites. The map will also, he adds, be a reference for exploration of the Jovian system.

NASA and the European Space Agency are currently developing a future voyage: the Europa Jupiter System Mission would include orbiters of Ganymede as well as the icy satellite Europa.

"A primary goal of the next flagship mission to the Jupiter system will be to characterize, in detail, the geophysical, compositional, geological, and external processes that affect icy satellites," Patterson said. "This map will be an invaluable tool in determining how best to address those goals for Ganymede.""<

Map pic:
http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=090915-ganymede-map-02.jpg&cap=A+global+image+mosaic+of+Jupiter%27s+moon%2C+Ganymede+created+with+images+from+the+Voyager+and+Galileo+missions.+Credit%3A+Wes+Patterson

posted in Astronomy - 0 replies

NASA Creates Anti-Gravity Field, Makes Lab Rats Levitate

freetheweed — Thu, 10 Sep 2009 17:26:58 GMT

Not exactly astronomy but I'm sure we'll find applications for it in space soon enough

http://gizmodo.com/5356473/nasa-creates-anti%20gravity-field-makes-lab-rats-levitate

NASA scientists have created an anti-gravity field that works at room temperature, which is a big Where's My Back to the Future Skateboard breakthrough. The only problem is that it only works on mice. Mice high as kites, in fact.

Scientists at the Jet Propulsion Laboratory in Pasadena, California, have created a superconducting magnet that generates enough energy to lift small animals off the floor. The magnet pushes the water inside the animals up, making them fly. The amazing fact is that it works at room temperature—not the ultra-cooled down environments typical of these magnets—and it's large enough to make rodents to levitate.

The mice were high in more than one way, though. According to researcher Yuanming Liu, the "first mouse actually kicked around and started to spin, and without friction, it could spin faster and faster, and we think that made it even more disoriented." So they gave a mild sedative to the next mouse, who was happy to float.

posted in Astronomy - 11 replies

Kepler could find moons?

idea1407 — Thu, 03 Sep 2009 18:28:59 GMT

Space.com article:
http://www.space.com/scienceastronomy/090903-kepler-moons.html

>"Kepler Telescope Could Find Habitable Moons
By SPACE.com Staff

posted: 03 September 2009
11:21 am ET

NASA's planet-hunting Kepler telescope, which astronomers hope will find Earth-like planets orbiting other stars, might also find habitable moons in other solar systems, new research suggests.

Kepler's primary mission is to monitor thousands of stars looking for characteristic dips in their brightness as orbiting planets pass in front of them in so-called "transit" events.

The orbiting observatory, launched in March, already detected the giant extrasolar planet HAT-P-7b within its first 10 days of taking data. The planet had previously been discovered by ground-based telescopes, but the observations showed Kepler works as expected.

While ground-based observatories, and even some space telescopes, such as Spitzer and Hubble, can find Jupiter-sized extrasolar planets, Kepler is the first telescope aimed at detecting alien worlds closer to the size of our own home planet.

One astronomer suggests that Kepler's capabilities may even be able to detect so-called "exo-moons."

Modeling moons

David Kipping of University College London has already devised a method for detecting exomoons but no-one was sure whether it could really be used with current technology. He and his team have now modeled the properties of the instruments on Kepler, simulating the expected signal strength that a habitable moon would generate.

An exomoon's gravity tugs on the planet it orbits, making the planet wobble during its orbit around its host star. The resulting changes in the position and velocity of the planet should be detectable by Kepler through accurate timing of the transits.

The scientists considered a wide range of possible planetary systems and found that a fluffy Saturn-like planet, which would be low in mass for its size, gives the best possible chance for detecting a moon, rather than a denser Jupiter-like world. This is because planets like Saturn are large – blocking out a lot of light as they pass in front of their star – but very light, meaning they will wobble much more than a heavy planet.

If the Saturn-like planet is at the right distance from its star, then the temperature will allow liquid water to be stable on any sufficiently large moons in orbit around it. Such water-bearing moons might be habitable for life.

"For the first time, we have demonstrated that potentially habitable moons up to hundreds of light years away may be detected with current instrumentation," Kipping said.

Millions of moons possible

The team found that habitable exomoons down to 0.2 times the mass of the Earth are readily detectable with Kepler.

"As we ran the simulations, even we were surprised that moons as small as one-fifth of the Earth's mass could be spotted," Kipping said.

While it is not known if habitable exomoons are common in the galaxy, the observatory could potentially look for Earth-mass habitable moons around 25,000 stars up to 500 light-years away from the sun. In the whole sky, there should be millions of stars which could be surveyed for habitable exomoons with present technology.

"It seems probable that many thousands, possibly millions, of habitable exomoons exist in the Galaxy and now we can start to look for them," Kipping said.

The team's findings will be detailed later this month in the journal Monthly Notices of the Royal Astronomical Society."<

posted in Astronomy - 1 reply

New Space Tribe

idea1407 — Sat, 12 Sep 2009 19:05:17 GMT

Commercial Space is changing with the New Space companies like Virgin Galactic and SpaceX. So I am putting out an open invitation to all who is interested in the subject.

Recently Posts:

Re: SpaceX - $50M for Commerical Space crewed services:
http://tribes.tribe.net/newspace/thread/b8e298ac-a44e-4912-a6cc-3135e3119de6#387d0fdb-afbb-484e-9ddb-2c9923411a90

Commercial Crew Development
http://tribes.tribe.net/newspace/thread/87467f7c-a765-47f2-8597-8c782f89d66c#fa333654-4879-402f-95a9-62c1b81d45a3

posted in Astronomy - 0 replies

Galaxies Demand a Stellar Recount

Serge — Thu, 10 Sep 2009 20:04:52 GMT

Feature, August 19, 2009

For decades, astronomers have gone about their business of studying the cosmos with the assumption that stars of certain sizes form in certain quantities. Like grocery stores selling melons alone, and blueberries in bags of dozens or more, the universe was thought to create stars in specific bundles. In other words, the proportion of small to big stars was thought to be fixed. For every star 20 or more times as massive as the sun, for example, there should be 500 stars with the sun's mass or less.

This belief, based on years of research, has been tipped on its side with new data from NASA's Galaxy Evolution Explorer. The ultraviolet telescope has found proof that small stars come in even bigger bundles than previously believed; for example, in some places in the cosmos, about 2,000 low-mass stars may form for each massive star. The little stars were there all along but masked by massive, brighter stars.

"What this paper is showing is that some of the standard assumptions that we've had – that the brightest stars tell you about the whole population of stars – this doesn't seem to work, at least not in a constant way," said Gerhardt R. Meurer, principal investigator on the study and a research scientist at Johns Hopkins University, Baltimore, Md.

Astronomers have long known that many stars are too dim to be seen in the glare of their brighter, more massive counterparts. Though the smaller, lighter stars outnumber the big ones, they are harder to see. Going back to a grocery story analogy, the melons grab your eyes, even though the total weight of the blueberries may be more.

Beginning in the 1950s, astronomers came up with a method for counting all the stars in a region, even the ones they couldn't detect. They devised a sort of stellar budget, an equation called the "stellar initial mass function," to estimate the total number of stars in an area of the sky based on the light from only the brightest and most massive. For every large star formed, a set number of smaller ones were thought to have been created regardless of where the stars sat in the universe.

"We tried to understand properties of galaxies and their mass by looking at the light we can see," Meurer said.

But this common assumption has been leading astronomers astray, said Meurer, especially in galaxies that are intrinsically small and faint.

To understand the problem, imagine trying to estimate the population on Earth by observing light emitted at night. Looking from above toward North America or Europe, the regions where more people live light up like signposts. Los Angeles, for example, is easily visible to a scientist working on the International Space Station. However, if this method were applied to regions where people have limited electricity, populations would be starkly underestimated, for example in some sections of Africa.

The same can be said of galaxies, whose speckles of light in the dark of space can be misleading. Meurer and his team used ultraviolet images from the Galaxy Evolution Explorer and carefully filtered red-light images from telescopes at the Cerro Tololo International Observatory in Chile to show that many galaxies do not form a lot of massive stars, yet still have plenty of lower-mass counterparts. The ultraviolet images are sensitive to somewhat small stars three times or more massive than the sun, while the filtered optical images are only sensitive to the largest stars with 20 or more times the mass of the sun.

The effects are particularly important in parts of the universe where stars are spread out over a larger volume -- the rural Africa of the cosmos. There could be about four times as many stars in these regions than previously estimated.

"Especially in these galaxies that seem small and piddling, there can be a lot more mass in lower mass stars than we had previously expected from what we could see from the brightest, youngest stars," Meurer said. "But we can now reduce these errors using satellites like the Galaxy Evolution Explorer."

This research was published in the April 10, 2009, issue of Astrophysical Journal.

-end-

From: subscription email

posted in Astronomy - 1 reply

Hubble back in the saddle!

idea1407 — Thu, 10 Sep 2009 18:50:02 GMT

http://www.space.com/scienceastronomy/090909-new-hubble-images.html

>"Hubble Telescope is Back: Fantastic New Images Released
By Andrea Thompson
Senior Writer
posted: 09 September 2009
11:22 am ET

NASA's Hubble Space Telescope is back in action after its most recent upgrade, with a spectacular array of new images showing off the telescope's new capabilities.

Among the first images – a closely guarded secret until today – is one of galaxy NGC 6217. The picture was taken with NASA's newly refurbished Advanced Camera for Surveys (ACS).

This is "the day many of us have all been waiting for to celebrate Hubble's new beginning," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at NASA Headquarters in Washington, D.C.

Hubble also snapped pictures of a group of five galaxies, a densely packed star cluster, an eerie "pillar of creation," and a "butterfly" nebula.

Scientists also released spectroscopic observations that slice across billions of light-years to probe the cosmic-web structure of the universe and map the distribution of elements that are fundamental to life as we know it.

Sen. Barbara A. Mikulski, D-Md., who has provided key support for Hubble and NASA in Congress, unveiled the images at NASA Headquarters. She was given the honorary title "Godmother of Hubble." Mikulski's district includes the Space Telescope Science Institute in Baltimore, where Hubble images are processed.

"I fought for the Hubble repair mission because Hubble is the people's telescope," said Mikulski, chairwoman of the Commerce, Justice and Science Appropriations Subcommittee that funds NASA.

Hubble's new instruments, including the Wide Field Camera 3, a new super-sensitive spectrograph, were installed on the 19-year-old telescope by shuttle astronauts during a 13-day service mission in May. The mission, which was initially cancelled in 2004 due to safety concerns after the 2003 Columbia shuttle disaster, also revived two instruments — Hubble's main ACS and a versatile imaging spectrograph — that were never designed to be fixed in space.

The new instruments are more sensitive to light and, therefore, will improve Hubble's observing efficiency significantly. It is able to complete observations in a fraction of the time that was needed with prior generations of Hubble instruments.

The WFC3 was actually used to take a picture of Jupiter's new black spot — thought to have been caused by a comet collision — back in July, but the camera wasn't yet fully calibrated then. WFC3 also took new images of the Omega Centauri star cluster in our galaxy, in which the contrast between hot and cool stars can vividly be seen, and the Butterfly Nebula, for which astronomers used the new filters on the camera to see the envelope of gas expanding away from this planetary nebula.

"We couldn't be happier about the way things have gone," Bob O'Connell, chair of the science oversight committee for the Wide Field Camera 3 at the University of Virginia. "We're fully confident the camera is working as it was intended to work."

Images taken with the new Cosmic Origins Spectrograph were taken in one-tenth of the time of Hubble's older spectrograph, which will allow scientists to view 10 times as many targets or look at targets one-tenth as bright, said James Green, the COS principal investigator at the University of Colorado. Scientists hope to build a catalogue of hundreds or thousands of targets and map the distribution of matter throughout the universe.

Hubble will also be able to continue observations of Eta Carinae, one of the most massive stars in the galaxy (and actually a pair of stars), that were suspended by instrument failure in 2004, said David Leckrone, senior project scientist for Hubble at NASA's Goddard Space Flight Center in Greenbelt, Md. Eta Carinae has erupted before and is expected to do so again.

Despite a few bumps in the three-month checkout, Hubble's systems and instruments are all up and running now.

NASA's new administrator Charlie Bolden was also on hand to congratulate the scientists and astronauts on Hubble's new lease on life. Bolden was one of the astronauts on the shuttle mission that deployed Hubble in 1990.

"Hubble has a special place in my heart," Bolden said. Through Hubble's past and future observations, "our view of the universe and our place within it will never be the same," he added."<

posted in Astronomy - 1 reply

NASA Researchers Make First Discovery of Life's Building Block in Comet

Serge — Thu, 10 Sep 2009 20:01:12 GMT

DC Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

Nancy Neal Jones
Goddard Space Flight Center, Md.
301-286-0039/5017
nancy.n.jones@nasa.gov

News release: 2009-126, August 17, 2009

PASADENA, Calif. -- NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.

"Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet," said Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Md. "Our discovery supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts."

Elsila is the lead author of a paper on this research accepted for publication in the journal Meteoritics and Planetary Science. The research was presented during the meeting of the American Chemical Society at the Marriott Metro Center in Washington, D.C., August 16.

"The discovery of glycine in a comet supports the idea that the fundamental building blocks of life are prevalent in space, and strengthens the argument that life in the universe may be common rather than rare," said Carl Pilcher, director of the NASA Astrobiology Institute, which co-funded the research.

Proteins are the workhorse molecules of life, used in everything from structures like hair to enzymes, the catalysts that speed up or regulate chemical reactions. Just as the 26 letters of the alphabet are arranged in limitless combinations to make words, life uses 20 different amino acids in a huge variety of arrangements to build millions of different proteins.

Stardust passed through dense gas and dust surrounding the icy nucleus of Wild 2 (pronounced "Vilt-2") on Jan. 2, 2004. As the spacecraft flew through this material, a special collection grid filled with aerogel – a novel sponge-like material that's more than 99 percent empty space – gently captured samples of the comet's gas and dust. The grid was stowed in a capsule that detached from the spacecraft and parachuted to Earth on Jan. 15, 2006. Since then, scientists around the world have been busy analyzing the samples to learn the secrets of comet formation and our solar system's history.

"We actually analyzed aluminum foil from the sides of tiny chambers that hold the aerogel in the collection grid," said Elsila. "As gas molecules passed through the aerogel, some stuck to the foil. We spent two years testing and developing our equipment to make it accurate and sensitive enough to analyze such incredibly tiny samples."

Earlier, preliminary analysis in the Goddard labs detected glycine in both the foil and a sample of the aerogel. However, since glycine is used by terrestrial life, at first the team was unable to rule out contamination from sources on Earth. "It was possible that the glycine we found originated from handling or manufacture of the Stardust spacecraft itself," said Elsila. The new research used isotopic analysis of the foil to rule out that possibility.

Isotopes are versions of an element with different weights or masses; for example, the most common carbon atom, Carbon 12, has six protons and six neutrons in its center (nucleus). However, the Carbon 13 isotope is heavier because it has an extra neutron in its nucleus. A glycine molecule from space will tend to have more of the heavier Carbon 13 atoms in it than glycine that's from Earth. That is what the team found. "We discovered that the Stardust-returned glycine has an extraterrestrial carbon isotope signature, indicating that it originated on the comet," said Elsila.

The team includes Daniel Glavin and Jason Dworkin of NASA Goddard. "Based on the foil and aerogel results it is highly probable that the entire comet-exposed side of the Stardust sample collection grid is coated with glycine that formed in space," adds Glavin.

"The discovery of amino acids in the returned comet sample is very exciting and profound," said Stardust Principal Investigator Donald E. Brownlee, a professor at the University of Washington, Seattle. "It is also a remarkable triumph that highlights the advancing capabilities of laboratory studies of primitive extraterrestrial materials."

The research was funded by the NASA Stardust Sample Analysis program and the NASA Astrobiology Institute. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Stardust mission for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, developed and operated the spacecraft.

For images, visit: http://www.nasa.gov/mission_pages/stardust/news/stardust_amino_acid.html

-end-

From: subscription email

posted in Astronomy - 0 replies

HTV flight

idea1407 — Mon, 07 Sep 2009 21:14:50 GMT

http://www.space.com/missionlaunches/090904-japan-htv-ready.html

>"Japan's First Space Cargo Ship Ready to Fly
By Tariq Malik
Managing Editor
posted: 05 September 2009
01:29 pm ET

Japan's first unmanned spacecraft to haul cargo to the International Space Station (ISS) is nearly ready for its maiden launch next week.

The new cargo ship is poised to launch toward the station on Sept. 10 at 1:01 p.m. EDT (1701 GMT) from the Tanegashima Space Center in southern Japan on a shakedown cruise. If all goes well, the inaugural spacecraft, called the H-2 Transfer Vehicle 1 (HTV-1), should arrive at the station on Sept. 17.

The spacecraft was built by JAXA, Japan's space agency, and will launch atop the country's brand new H-2B rocket. It will be early Sept. 11 Local Time at the Japanese launch site at the time of liftoff.

"JAXA is ready to carry out the important HTV-1 mission as a new contribution to the ISS program," said Masazumi Miyake, director of the JAXA office at NASA's Johnson Space Center in Houston, in a Wednesday briefing.

JAXA mission managers are expected to hold a series of final readiness reviews for HTV-1 and its rocket booster to make sure it's ready for launch day. "<

posted in Astronomy - 2 replies

Pics of Triton

idea1407 — Wed, 09 Sep 2009 14:08:26 GMT

http://www.space.com/scienceastronomy/090908-st-neptune-pictures.html

>"New Pictures of Neptune's Moon Triton

By Clara Moskowitz
Staff Writer
posted: 08 September 2009
08:50 am ET

NASA released new pictures of Neptune's freezing moon Triton, made from data taken by the Voyager 2 spacecraft on its way out of the solar system in 1989.

The close-up shots reveal Triton's pockmarked surface, covered with crater scars from years of space rock impacts, as well as smooth volcanic plains, mounds and round pits formed by icy lava flows.

The photographs were released to commemorate the 20-year anniversary of the Voyager flyby of the moon, the last solid object visited by the spacecraft. The images were made using topographic maps derived from Voyager 2 photographs.

Among its discoveries at the moon, Voyager 2 revealed that Triton has active geysers. And with surface temperatures at minus 391 degrees Fahrenheit (minus 235 degrees Celsius), Neptune's largest moon is one of the coolest objects in the solar system.

The unmanned Voyager 2 probe launched in 1977 on a grand tour of the solar system, visiting Jupiter, Saturn, Uranus, and Neptune, as well as many of their moons, before moving on to interstellar space.

The probe is currently about 8.4 billion miles (13.5 billion km) from the sun, or almost 90 times the distance between the sun and Earth.

Voyager 2 and its sister, Voyager 1 (also launched in 1977, and currently the farthest away man-made object, at about 10 billion miles, or 16 billion km from the sun) are still operational and still transmitting data.

Both probes carry with them golden phonograph records with sounds chosen to communicate a sampling of humanity to any extraterrestrial life they may encounter. The contents, which include greetings in 55 languages, as well as music such as Bach's Brandenburg Concerto, gamelan music from Indonesia, Louis Armstrong's "Melancholy Blues," and many others, were chosen by a NASA committee headed by Carl Sagan."<

posted in Astronomy - 1 reply

Saturn Moon Could Power 150 Billion Labor Day Barbecues

Serge — Mon, 07 Sep 2009 01:09:49 GMT

Feature,
September 04, 2009

Since its discovery by Dutch astronomer Christiaan Huygens in 1655, Saturn's most massive moon, Titan, has been known as a place of mystery and intrigue. The large, cloud-enshrouded moon is such a scientific enigma that for the past five years, it has been targeted by NASAs Cassini spacecraft with more than 60 probing flybys. One of its latest findings could be a valuable asset to future generations of space explorers hunting for materials to whip up a Labor Day barbecue.

“Titan’s atmosphere is extremely rich in an assortment of hydrocarbon chemicals, including propane, which we use to fill our barbecue tanks,” said Cassini scientist Conor Nixon of the University of Maryland, College Park. "Titan’s atmospheric inventory would fuel about 150 billion barbecue cookouts, enough for several thousand years of Labor Days.”

For those who are burger, barbecue or Titan challenged, propane is a three-carbon alkane (a chemical compound consisting of carbon and hydrogen), that is non-toxic and heavier than air. With its low boiling point of minus 43.6 degrees Fahrenheit (minus 42 degrees Centigrade), propane vaporizes as soon as it is released from its pressurized container. Here on Earth, propane is commonly used as a fuel for forklifts, flamethrowers, residential central heating, portable stoves, hot air balloons, and – of course – barbecues. On other worlds propane is an untapped resource.

This gas of many terrestrial uses was first discovered in Titan's atmosphere back in 1980 when NASA's Voyager 1 spacecraft flew past the Saturnian system. Over the years, both ground and space-based instruments have added to the research, but accurately quantifying the amount of propane on Titan has proved elusive. Then, in 2004, the Cassini spacecraft entered orbit around Saturn.

Measuring the amount of propane on Titan is important to scientists because the gas is a very complex molecule, and its signature in the infrared spectrum is close to those of several molecules scientists are hoping to discover in Titan's atmosphere.

"It was not so much that measuring propane was our endgame, but it helps enormously in our hunt for other complex molecules," said Nixon. "These include pyrimidines that are potential building blocks for biological molecules, such as the nuceleobases of our DNA.” If we can detect them on Titan, that would be very significant."

Propane on Titan was measured using data from Cassini's Composite Infrared Spectrometer instrument. During multiple flybys of the moon between June 2004 and June 2008, the instrument measured infrared light from the edge of Titan's atmosphere. After a detailed analysis of the gas's characteristic ‘emission bands’ or signature, using computer predictions backed by the latest laboratory research into its infrared spectrum, the Composite Infrared Spectrometer team came up with an estimate of the amount of propane in Titan’s atmosphere So exactly how much propane does it take to fire 150 billion cookouts?

"We estimate there are nearly 700 million barrels of propane on Titan, said Nixon. "That is enough to fill six-billion 20-pound tanks of liquefied propane gas. It sounds like a huge amount, but that would satisfy total U.S. consumption of propane for only 18 months."

Which still leaves, with regards to Saturn's biggest moon, one Labor Day staple still to be determined. How many hamburgers could future generations of outer-planet explorers grill using Titan’s atmospheric propane?

"A dozen at a time, that’s two trillion hamburgers," said Cassini’s Nixon, "assuming you stop at medium-well."

Nixon is the lead author on a paper about propane on Titan to be published in an upcoming issue of Planetary and Space Science.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Cassini orbiter was designed, developed and assembled at JPL. JPL manages the mission for the Science Mission Directorate at NASA Headquarters in Washington. Cassini's Composite Infrared Spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md.

More information about the Cassini mission is available at http://www.nasa.gov/cassini or http://saturn.jpl.nasa.gov .

Doing the math: How do we get from “150 billion barbeque cookouts” to “two trillion” burgers?

You can fit 700 million barrels of propane into about six billion 20-pound tanks of liquefied propane gas (LPG). As most Labor Day cookouts will probably occur on this planet, we will use Earth as our barbecue laboratory. On Earth, a full tank of LPG burns for about nine hours – enough time to turn out 25 to 30 meals. That brings us to about 150 to 180 billion meals. If you average 12 medium-well patties per meal, then we’re talking about 2 trillion burgers. When it comes to figuring out how many hot dogs could be cooked, you’re on your own.

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From: subscription email

posted in Astronomy - 3 replies

Milky Way Expected to Survive a Beating

Serge — Mon, 07 Sep 2009 17:59:02 GMT

By Clara Moskowitz
Staff Writer
posted: 07 September 2009
09:07 am ET

Though the Milky Way is taking a good beating from nearby mini-galaxies that sometimes slam into it, our galaxy is not likely to de destroyed by this process as some scientists had predicted, a new study finds.

Circling around the Milky Way, http://www.space.com/scienceastronomy/060227_mm_milky_way_tour.html , are between 20 and 25 known satellite dwarf galaxies, http://www.space.com/scienceastronomy/090804-st-dwarf-spheroidal-galaxies.html , which are smaller clumps of stars bound in orbit around the Milky Way by gravitational attraction.

Some pessimists predicted, http://www.space.com/scienceastronomy/astronomy/galaxy_collides_020507-1.html , the Milky Way was doomed to a grisly death by dismemberment if enough of these galaxies collide with it. In fact, scientists think many satellite galaxies have already rammed into the Milky Way, though so far it has endured.

A new computer simulation indicates that rather than tearing apart a galaxy, http://www.space.com/common/media/video/player.php?videoRef=070509Galaxy_collide , collisions with dwarf galaxies serve to puff up the host's pancake-shaped galactic disk. Indeed, evidence of this puffiness has been found in the form of rings and flares of stars around the edges of other galaxies' disks.

"Our simulations showed that the satellite galaxy impacts don't destroy spiral galaxies — they actually drive their evolution, by producing this flared shape and creating stellar rings — spectacular rings of stars that we've seen in many spiral galaxies in the universe," said study leader Stelios Kazantzidis, an astronomer at Ohio State University.

Though our galaxy may not be in danger from dwarf galaxies, astronomers do expect it to eventually collide with the nearest full-size galaxy, Andromeda. In a few billion years, the two spirals should smash into each other head on.

"The collision with Andromeda is a collision between two essentially equal-mass galaxies, whereas satellite bombardment involves encounters with much smaller systems compared to the Milky Way," Kazantzidis told SPACE.com.

Luckily, even that fender bender doesn't necessarily spell the end for the galaxies' inhabitants. Stars are generally spaced wide enough apart within the galaxies that after the merger, most individual stars should intermingle without actually crashing into each other.

In fact, the merging will likely set off a firestorm of new star formation, adding to the richness of the two melded galaxies.

The new simulation helps scientists understand how smaller collisions affect a galaxy's development.

"We can't know for sure what's going to happen to the Milky Way, but we can say that our findings apply to a broad class of galaxies similar to our own," Kazantzidis said.

The model is the most detailed to date of collisions between spiral galaxies and satellites. It revealed the kind of detailed features that should result from these impacts, which align well with observed characteristics of other galaxies seen in the universe.

"Every spiral galaxy has a complex formation and evolutionary history," Kazantzidis said. "We would hope to understand exactly how the Milky Way formed and how it will evolve...

The research is detailed in two papers published in the Astrophysical Journal in August 2009 and November 2008.

Original Story: http://www.space.com/scienceastronomy/090907-mm-milky-way-survive.html

posted in Astronomy - 1 reply

Free Public Lectures Will Preview Next Mars Landing

Serge — Wed, 19 Aug 2009 18:46:44 GMT

Guy Webster (818) 354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
Guy.webster@jpl.nasa.gov

News release: 2009-128, August 18, 2009

PASADENA, Calif. -- Two free public programs in Pasadena this week will explain why previous methods of landing on Mars would not work for the next Mars rover and will describe how engineers developed a new sky-crane system for this mission, NASA's Mars Science Laboratory.

Tom Rivellini of NASA's Jet Propulsion Laboratory in Pasadena, will present illustrated talks about Mars landing methods on Thursday, Aug. 20, at JPL, with a live webcast, and on Friday, Aug. 21, at Pasadena City College. Both lectures will begin at 7 p.m. PDT.

Rivellini is one of JPL's principal mechanical engineers for spacecraft descent and landing systems.

In 2012, the Mars Science Laboratory mission's rover, Curiosity, will use a heat shield and parachute for initial phases of its descent through the Martian atmosphere. Then a rocket-powered descent stage will slow almost to a hover and unspool a tether, lowering the rover directly onto the surface.

Seating is first-come, first-served. The Thursday lecture will be in JPL's von Kármán Auditorium. JPL is at 4800 Oak Grove Dr., off the Oak Grove Drive exit of the 210 (Foothill) Freeway. The Friday lecture will be in Pasadena City College's Vosloh Forum, 1570 E. Colorado Blvd. For more information, call (818) 354-0112.

For information on how to view the live webcast on Thursday and to see an archived video later, visit http://www.jpl.nasa.gov/events/lectures.cfm?year=2009&month=8 . More information about the Mars Science Laboratory mission is at http://mars.jpl.nasa.gov/msl/ .

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posted in Astronomy - 4 replies

Lack of Gravity Waves

idea1407 — Tue, 01 Sep 2009 16:48:21 GMT

http://www.space.com/scienceastronomy/090819-gravitational-waves.html

>"Lack of Gravity Waves Puts Limits on Exotic Cosmology Theories
By Clara Moskowitz
Staff Writer
posted: 19 August 2009
02:36 pm ET

This time, scientists are excited to find nothing.

In results announced today, a huge physics experiment built to detect gravitational waves has yet to find any.

Rather than be disappointed by the null findings, physicists say the results were expected, and in fact help them narrow down possibilities for what the universe was like just after it was born.

The Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration (LIGO) is a set of instruments in Louisiana and Washington built to search for evidence of gravitational waves, which are theoretical ripples in space-time thought to be caused by the acceleration of mass. No one has yet directly detected these waves, though they are predicted by Einstein's theory of General Relativity, and are widely thought to permeate our universe.

In theory, every time mass accelerates - even when you rise up out of your chair - the curvature of space-time changes, and ripples are produced. However, the gravitational waves produced by one person are so small as to be negligible. The waves produced by large masses, though, such as the collision of two black holes or a large supernova explosion, could be large enough to be detected."<

posted in Astronomy - 5 replies

Solar Systems Warped by Interstellar Wind

idea1407 — Tue, 01 Sep 2009 16:21:00 GMT

A Space.com article:

http://www.space.com/scienceastronomy/090901-st-warped-debris-disk.html

>"Solar Systems Warped by Interstellar Wind

By SPACE.com Staff

posted: 01 September 2009
10:56 am ET

Close encounters with interstellar gas could have given the dust-filled disks of solar systems — where planets are thought to form — the odd shapes that some of them have taken on, a new study suggests.

Stars across the galaxy have disks of dusty debris generated by the collisions of small comet- and asteroid-like bodies orbiting each star.

Astronomers have noticed that many of these debris disks are a bit wonky-looking, with lobes of dust sticking out in odd directions. One team noticed just such an oddly-shaped disk while using the Hubble Space Telescope to investigate the composition of the dust around the star HD 32297, which lies 340 light-years away from Earth in the constellation Orion.

John Debes of NASA's Goddard Space Flight Center in Greenbelt, Md., noticed that the interior portion of this star's dusty disk — a region comparable to the size of our own solar system — was warped in a way that was similar to other distant star systems.

Astronomers have previously attributed these warped shapes to the presence of undiscovered planets or past encounters with another star. But Debes and his colleagues used a model to show that the odd shapes aren't likely due to one of these exotic factors, but instead are likely caused by the interstellar environment that the star and its attendant disk are moving through.

"It's important to consider the ecology of these debris disks before running to such conclusions, and this model explains a lot of the weirdly shaped disks we see," Debes said."<

posted in Astronomy - 5 replies

ISRO loses radio contact with Chandrayaan-1

freetheweed — Sat, 29 Aug 2009 20:55:58 GMT

http://www.hindu.com/2009/08/30/stories/2009083053760100.htm

ISRO loses radio contact with Chandrayaan-1

T.S. Subramanian

India’s first moon mission cut short; a lot of data gained

CHENNAI: In a major blow to India’s maiden mission to the moon, the Indian Space Research Organisation (ISRO) abruptly lost contact with Chandrayaan-1 at 01.30 a.m. on Saturday. This means no command can be given to the spacecraft and no data, including images of the moon’s surface, are being received from it.

The Chandrayaan-1 mission has come to an end in ten months instead of its slated life of two years.

“We are not able to give commands to the spacecraft,” S. Satish, Director, Publications and Public Relations Department of ISRO, told The Hindu. “We are not able to establish communication with it, with the result that we do not know what is happening.”

The Indian Deep Space Network (IDSN) at Byalalu village, near Bangalore, received data from Chandrayaan-1 till an hour before radio contact was lost. The IDSN, with its huge antennae with diameters of 32 metres and 18 metres, is the hub of communications from the ground with the spacecraft. It is from Byalalu that commands were radioed to the spacecraft to perform various manoeuvres. Images from Chandrayaan-1 were also received here.

India’s first spacecraft to the moon was launched on October 22, 2008 from Sriharikota. An ISRO press release noted on Saturday that the spacecraft had completed 312 days in orbit, making more than 3,400 orbits around the moon. It provided a large amount of data from its sophisticated instruments such as the Terrain Mapping Camera, the Hyper-Spectral Imager, the Moon Mineralogy Mapper and so on. ISRO claimed that the mission had met most of its scientific objectives.

Chandrayaan-1 sent back more than 70,000 images of the lunar surface, which provided breathtaking views of lunar mountains and craters, especially craters in the permanently shadowed areas of the moon’s polar region. It also collected data on the chemical and mineral content of the moon’s soil.

But the troubles that have cut short the life of the moon mission began in November itself when the spacecraft’s power subsystems started failing one by one. In April, the mission went into a crisis, with the primary star-sensor and the backup star-sensor failing. But top ISRO officials appeared keen to play down the setbacks, with a May 20 press release making no mention of the failure of the star-sensors and the power units.

Asked what could have gone wrong with the spacecraft, Mr. Satish said: “Some electronic sub-system could have malfunctioned. We are looking at the telemetry data and trying to find out what is the problem. Using the telemetry data [received till contact with the spacecraft was lost], the health of the spacecraft is being analysed. It is expected to throw light on the problem noticed. ISRO’s stations are trying to revive the spacecraft.”

Asked whether Chadrayaan-1 was drifting away from its orbit, Mr. Satish said it was “definitely in orbit.” However, if the present situation continued, the orbit could be disrupted.

ISRO experts explained that all communication with Chandrayaan-1 and the receipt of data from it were handled through on-board electronic systems. “If radio contact with Chandrayaan is suddenly lost,” a top expert pointed out, “only electronic systems on the spacecraft could have failed. Otherwise, this could not have happened. From the symptoms, it looks as if the electronics failed.”

A Polar Satellite Launch Vehicle (PSLV) of ISRO put Chandrayaan-1 in its initial orbit. The spacecraft carried 11 instruments on board. One of them named the Moon Impact Probe (MIP) “impacted” on the lunar surface on November 14, 2008, signalling India’s success in reaching the moon.

posted in Astronomy - 10 replies

Space shuttle lifts off for ISS

freetheweed — Sun, 30 Aug 2009 10:29:18 GMT

http://news.bbc.co.uk/2/hi/science/nature/8228089.stm

Space shuttle lifts off for ISS

Space shuttle takes off at the third attempt

Nasa has launched the US shuttle Discovery for a mission to the International Space Station (ISS), with seven astronauts on board.

It lifted off from the Kennedy Space Center in Florida at 2359 EDT Friday (0359 GMT Saturday).

Two previous attempts to launch the orbiter had been postponed by a mix of bad weather and a technical glitch affecting its main propulsion system.

Discovery's mission will be the 30th flight dedicated to ISS maintenance.

Science equipment and a freezer to store research samples are among the items on board.

It also carries a new sleeping compartment, an air purification system and a treadmill to help maintain astronauts' health.

The shuttle entered orbit eight-and-a-half minutes after launch, and is due to arrive at the ISS on Sunday night.

Six sorties

Nasa plans an additional six sorties to the orbiting platform before retiring its re-useable spaceship fleet at the end of next year or early in 2011.

Managers had been discussing an early Friday flight but decided to give their engineers an extra 23 hours to study the hydrogen stop-drain fuel-valve problem that thwarted the second launch effort on Wednesday.

Engineers now believe the unexpected signals they were getting from the propulsion system while filling the orbiter's giant external tank on Tuesday were related to a errant sensor.

Heavy rain and lightning had intervened at the first launch attempt on Tuesday morning.

Discovery's 13-day mission is scheduled to include three spacewalks to replace exterior science experiments, prepare the platform for the arrival of a new module next year, and to install a new ammonia storage tank and return the used one.

Ammonia is used to move excess heat from inside the station to the radiators outside.

Discovery will also drop off US astronaut Nicole Stott for a three-month stay on the ISS, and pick up colleague Tim Kopra for the ride home. Kopra has been living on the platform for the past six weeks.

The mission is commanded by Rick Sturckow.

posted in Astronomy - 3 replies

Fog on Titan?

Hummingbird — Thu, 27 Aug 2009 20:37:39 GMT

http://www.mikebrownsplanets.com/2009/08/fog-titan-titan-fog-and-peer-review.html

"Titan has fog at the south pole! All of those bright sparkly reddish white patches are fog banks hanging out at the surface in Titan's late southern summer."

posted in Astronomy - 10 replies

Lost Moderator

Serge — Sat, 15 Aug 2009 06:55:47 GMT

Hello Everyone,
For a while by now, I have been trying to get in touch with Damian, this tribe's moderator, and it seems like he has abandoned it/us. His little red light is no longer on, (ever), and he does not reply to any PM's.
Therefore, due to the absence of ANY reasonable mean to get in touch with him, I am putting forward a request to elect a new moderator, and give my vote to Eric, ( http://people.tribe.net/idea1407 ). He has shown a keen interest in the topic here, as well as in his own, (related), tribe, while always being respectful of opinions of others, and ready to listen as well as actively participate in discussions.
...
Everyone is welcome to vote in this thread for a week, beginning now, 12:00 am, Saturday, August 14th.
The last vote will be counted in at 12:00 am, Saturday, August 21st, after which, I will contanct Tribe.net and inform them of the outcome of the elections.

Regards,
Serge

posted in Astronomy - 26 replies

Cosmic Rays

idea1407 — Thu, 27 Aug 2009 19:41:55 GMT

Space.com article:
http://www.space.com/scienceastronomy/090827-cosmic-rays.html

>"Death Rays From Space: How Bad Are They?
By Michael Schirber
Astrobiology Magazine
posted: 27 August 2009
11:53 am ET

Cosmic rays pour down on Earth like a constant rain. We don't much notice these high-energy particles, but they may have played a role in the evolution of life on our planet.

Some of the mass extinctions identified in the fossil record can be linked to an asteroid impact or increased volcanism, but many of the causes of those ancient die-offs are still open for debate.

"There may have been nearby astronomical goings-on that drastically increased the radiation on Earth," says Brian Fields from the University of Illinois.

A supernova going off 30 light-years away could cause such a jump in radiation on our planet that could directly, or indirectly, wipe out huge numbers of species. Currently researchers are looking for possible evidence for this sort of cosmic foul play.

"Just finding dead beasties is not proof of a nearby supernova," Fields says.

A hard rain is going to fall

Cosmic rays are mostly high-energy protons originating from supernova shock waves. We can't precisely trace where a cosmic ray came from because its trajectory is bent by magnetic fields. In fact, a typical cosmic ray will bounce inside the galaxy's magnetic field for millions of years before eventually colliding with something... like Earth.

"Every square centimeter on the top of the Earth's atmosphere is hit by several cosmic rays per second," Fields says. "This is forever going on."

None of these "primary" cosmic rays ever reach us on the ground. Instead, they collide with atoms in the upper atmosphere, creating a shower of lower energy "secondary" particles.

Secondary effects

At sea level, the majority of cosmic ray secondaries are highly penetrating muons. About 10,000 muons pass through our bodies every minute. Some of these muons will ionize molecules as they go through our flesh, occasionally leading to genetic mutations that may be harmful.

At present, the average human receives the equivalent of about 10 chest X-rays per year from cosmic rays. We shouldn't be alarmed by this, since it is just part of the natural background radiation under which humans and our ancestors have been exposed to for eons. Indeed, cosmic-ray-induced mutations may sometimes be beneficial.

"It is clear that in some way cosmic rays shaped evolution of organisms on Earth," says Franco Ferrari from the University of Szczecin in Poland.

In a recent issue of the journal Astrobiology, Ferrari and Ewa Szuszkiewicz from the same university reviewed what we know about cosmic rays, and they argue that the current biological relevance of these particles is not necessarily representative of the past.

"It is very likely that organisms of early Earth possessed DNA that was unstable and could easily mutate under external agents, more so, perhaps, than the DNA of present-day bacteria," the authors write.

Cosmic ray storm

Not only might biology have been more susceptible to mutation long ago, but the cosmic rays might have been more intense in the past, affecting both Earth's atmosphere and the life below.

One controversial theory suggests cosmic rays can increase cloud production. Cloudier skies bounce more sunlight off into space, cooling the planet and leading to widespread ecosystem changes. Another theory about increased cosmic radiation has nearly the opposite effect -- by stripping away our protective ozone layer, the Earth would have been blasted by more solar UV radiation. All that extra UV would have created hostile conditions for life.

Ozone depletion also could arise from a nearby gamma ray burst. However, the radiation flash would last only a second, and the ozone would recover after a few years. In contrast, cosmic rays from a nearby supernova would bombard Earth for at least 1,000 years, according to Fields.

"An organism might be able wait out a gamma ray burst, but cosmic rays are going to affect many generations," he says.

Near miss

One way to tell whether an extinction event was due to cosmic rays is to look for radioactive isotopes that would have formed in a nearby supernova and then were blown onto our planet by the associated blast wave.

In 1999, a group from the Technical University of Munich in Germany detected iron-60 in rock samples from the deep ocean. This extremely rare iron isotope is forged in the fires of supernovae. It is also radioactively unstable, with a half-life of 1.5 million years, so it must have come from a fairly recent supernova.

From the iron-60's location and concentration, the German group later calculated that the putative supernova went off 2.8 million years ago at a distance of about 100 light years away. Fields believes this was probably too far away to have caused an extinction-level event.

"I'd call it a near miss," he says.

The cosmic rays from this supernova may have had an effect on the climate, but to cause serious biological damage, a supernova would need to explode within about 30 light years of Earth.

Cosmic ray roulette

Although 30 light-years is small on a galactic scale, Fields thinks it likely that Earth has been caught in a supernova "kill radius" as many as a dozen times over our 4.5-billion-year history.

However, a nearby supernova is not the only way to increase the cosmic ray intensity. As our Sun orbits around the galactic center, it regularly passes through one of the galaxy's spiral arms where the cosmic ray radiation is higher than average, says Ferrari. Some researchers speculate that each passage through a spiral arm spawns an Ice Age on Earth through cosmic-ray-induced cloud formation.

In a similar vein, Melott and his colleagues found a possible link between the bobbing of our Sun up and down in the galactic plane and a 63-million-year cycle in fossil biodiversity. The hypothesis is that our solar system is exposed to more cosmic rays every time the solar system peaks out of one side of the galaxy.

However, Melott now thinks this bobbing may only play a small part, seeing as recent evidence points to a correlation between continental uplift and the observed biodiversity cycle.

More work is definitely needed to tie cosmic rays to extinction events. Melott says that the search continues for other radioactive isotope evidence of nearby supernovae, and his group is developing simulations of cosmic ray bombardment to see if there might be any recognizable pattern to the biological destruction.

"No one has calculated the full effects on the ground," he says."<

posted in Astronomy - 0 replies

Suicidal planet seems on death spiral into star

Serge — Wed, 26 Aug 2009 21:56:00 GMT

Science Writer Seth Borenstein,
Ap Science Writer – Wed Aug 26, 1:00 pm ET

WASHINGTON – Astronomers have found what appears to be a gigantic suicidal planet.

The odd, fiery planet is so close to its star and so large that it is triggering tremendous plasma tides on the star. Those powerful tides are in turn warping the planet's zippy less-than-a-day orbit around its star.

The result: an ever-closer tango of death, with the planet eventually spiraling into the star.

It's a slow death. The planet WASP-18b has maybe a million years to live, said planet discoverer Coel Hellier, a professor of astrophysics at the Keele University in England. Hellier's report on the suicidal planet is in Thursday's issue of the journal Nature.

"It's causing its own destruction by creating these tides," Hellier said.

The star is called WASP-18 and the planet is WASP-18b because of the Wide Angle Search for Planets team that found them.

The planet circles a star that is in the constellation Phoenix and is about 325 light-years away from Earth, which means it is in our galactic neighborhood. A light-year is about 5.8 trillion miles.

The planet is 1.9 million miles from its star, 1/50th of the distance between Earth and the sun, our star. And because of that the temperature is about 3,800 degrees.

Its size — 10 times bigger than Jupiter — and its proximity to its star make it likely to die, Hellier said.

Think of how the distant moon pulls Earth's oceans to form twice-daily tides. The effect the odd planet has on its star is thousands of times stronger, Hellier said. The star's tidal bulge of plasma may extend hundreds of miles, he said.

Like most planets outside our solar system, this planet was not seen directly by a telescope. Astronomers found it by seeing dips in light from the star every time the planet came between the star and Earth.

So far astronomers have found more than 370 planets outside the solar system. This one is "yet another weird one in the exoplanet menagerie," said planet specialist Alan Boss of the Carnegie Institution of Washington.

It's so unusual to find a suicidal planet that University of Maryland astronomer Douglas Hamilton questioned whether there was another explanation. While it is likely that this is a suicidal planet, Hamilton said it is also possible that some basic physics calculations that all astronomers rely on could be dead wrong.

The answer will become apparent in less than a decade if the planet seems to be further in a death spiral, he said.

___

On the Net

Nature: http://www.nature.com/nature
WASP group: http://www.superwasp.org/

From: Yahoo! News

posted in Astronomy - 5 replies

Tribe Preamble

idea1407 — Tue, 25 Aug 2009 02:59:52 GMT

The tribe preamble reads:
"Stargazing and planetwatching. Armchair cosmologists welcome. "

Should this be modified?

posted in Astronomy - 10 replies

South Korea launches its first rocket into space - 25 Aug 09

freetheweed — Tue, 25 Aug 2009 13:48:20 GMT

http://www.youtube.com/watch?v=Y49qg-033QU&feature=sub

South Korea has launched its first rocket into space just a week after the Naro Space Centre abandoned a first attempt because of a software glitch.

Seoul says the launch is meant to get the country into the satellite market, but North Korea remains skeptical.

Al Jazeera's Tony Birtley reports from Seoul, the South Korean capital.

http://news.bbc.co.uk/2/hi/asia-pacific/8219669.stm

S Korean launch 'partial success'

South Korea has launched its first space rocket, though a scientific satellite it was carrying failed to enter into its proper orbit.

South Korean officials described the launch as a "partial success".

Millions of South Koreans watched the launch, but it is being viewed with suspicion by North Korea.

The North was recently subjected to UN sanctions for its own rocket launch, which was widely regarded as a cover for a long-range missile test.

There was no immediate reaction from North Korea to Tuesday's launch.

Overshot orbit

South Korea's two-stage Naro rocket lifted off on Tuesday from an island off the south coast.

The satellite was placed into orbit but was not following its intended course, according to Science and Education Minster Ahn Byong-man.

"All aspects of the launch were normal, but the satellite exceeded its planned orbit," he was quoted as saying.

The satellite had reached an altitude of 360km (225 miles), rather than separating at the intended 302km, he said.

South Korean and Russian scientists were investigating the problem, he added.

Experts at the Korea Aerospace Research Institute were cited by local media as saying they were trying to track the satellite.

A statement from the science ministry called the launch a "partial success", while South Korean President Lee Myung-bak called it a "half-success".

'Potential military uses'

The rocket - 33m (108 ft) long and weighing some 140 tonnes - was the country's half-a-billion dollar bid to join the exclusive club of spacefaring nations.

Its Russian liquid-fuelled first-stage was said to have 1,700 kilonewtons of thrust at launch.

The second stage, burning a solid fuel, was produced by South Korean engineers.

Generating 80kN of thrust, it was intended to carry the Earth observation satellite into its final orbit.

South Korea initially planned to launch the rocket in late July, but delayed it several times due to technical problems.

South Korea has previously sent satellites into space using launch vehicles and rockets from other countries.

Seoul has rejected any comparison with Pyongyang's rocket launch and says its rocket is part of a peaceful civilian space programme.

But some security analysts have suggested a commercial space programme could still alter the long-term strategic balance in the region, as all rocket technology has potential military uses.

No North Korean satellite has been detected in space, although Pyongyang insists its rocket launch worked and the device is now orbiting the earth transmitting revolutionary melodies.

posted in Astronomy - 1 reply

Pluto...Superstar?

idea1407 — Mon, 24 Aug 2009 20:13:22 GMT

CNN article

http://www.cnn.com/2009/TECH/space/08/24/pluto.dwarf.planet/index.html

>"By A. Pawlowski
CNN
Decrease font Decrease font
Enlarge font Enlarge font

(CNN) -- For one of the farthest, coldest places in the solar system, Pluto sure stirs a lot of hot emotions right here on Earth.
This montage of images taken by Voyager shows, from left to right, Neptune, Uranus, Saturn and Jupiter.

This montage of images taken by Voyager shows, from left to right, Neptune, Uranus, Saturn and Jupiter.

It was three years ago Monday that the International Astronomical Union demoted Pluto from a planet to a dwarf planet, a decision that made jaws drop around the world.

An outcry followed, textbooks had to be rewritten, long-held beliefs were shattered, and many people felt our cosmic neighborhood just didn't seem the same with eight -- instead of nine --planets in the solar system.

Today, debate still rages over how to classify the little celestial body, along with others orbiting the sun, but the IAU stands by its definition.

"I think that most of the astronomical community has come to terms with the fact that we now know that the solar system has a continuous distribution of objects from very large down to very small," said Lars Lindberg Christensen, a spokesman for the IAU.

"We now know that what we call the different objects has to necessarily change with time."

Don't tell that to Plutophiles still seething about the decision. Some are even taking action.

Earlier this year, the Illinois Senate adopted a resolution declaring that Pluto was "unfairly downgraded" and restoring "full planetary status" to the celestial body as it "passes overhead through Illinois' night skies."

It also designated March 13, 2009, as "Pluto Day" in honor of the date that its discovery was announced in 1930. (In case you are wondering why the state is so passionate about Pluto: Clyde Tombaugh, who discovered the planet-now-dwarf-planet, was born in Illinois.)

Meanwhile, New Mexico's House of Representatives proclaimed February 18, 2009, as "Pluto is a Planet in New Mexico Day" and praised Tombaugh, who worked in the state for decades and died there in 1997.

Passionate about Pluto

Don't live in those states and want to make your voice heard? You can order "Plutophile" bumper stickers to proclaim your firm support for Pluto, print out a Pluto Fan Club card -- which allows you to declare, "In my heart, Pluto will always be a planet" -- or sign an online petition.
What's Pluto like?
• Pluto's average distance from the sun is about 3.6 billion miles

• The temperature on Pluto may be about -375 °F

• Pluto is mostly brown

• It takes Pluto 248 Earth years to travel once around the sun

• Pluto cannot be seen without a telescope

• Pluto's diameter is about 1,400 miles, smaller than Earth's moon

Source: World Book at NASA

Christensen said 90 percent of the critical e-mails and letters the IAU received after its decision in 2006 came from North America.

Astrophysicist Neil deGrasse Tyson, director of New York City's Hayden Planetarium and author of "The Pluto Files," believes there are two reasons why Americans are so engaged in the issue.

"Disney's dog Pluto was sketched the same year the cosmic object was discovered. And Pluto was discovered by an American. So here you have a recipe for Americans falling in love with a planet that really is just a tiny ice ball," Tyson told Time magazine.

Still, astronomers are divided about the best way to classify Pluto. See photos of other planets and find out what makes them stand out »

At the heart of the matter lies the question: What makes a planet in the solar system?

According to the IAU's definition, it must orbit the sun, it must be big enough for gravity to crush it into a nearly round shape, and it must clear the neighborhood around its orbit. In other words, it must be dominant enough to clear away objects in its orbital space, according to NASA.

This last point is what proved to be Pluto's demise as a planet: There are other competing objects in its orbit.

Crowded solar system?

Some scientists say that part of the definition doesn't make sense.

"It's kind of like, I'm going to tell you what your car is on the basis of how the traffic around you is behaving," said Mark Sykes, director of the Planetary Science Institute.

The more logical way to classify planets is the geophysical definition, which simply states that planets are round objects that orbit the sun, Sykes argues. The objects must still be big enough so that gravity crushes them into a ball.
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* Telescopes to show universe soon after Big Bang

"The problem with the geophysical definition is we might have a couple of dozen planets in the solar system as more are discovered in the distant reaches," Sykes said.

He believes the International Astronomical Union's definition won't stick around after NASA spacecraft reach Pluto and Ceres, a Texas-size asteroid in an orbit between Mars and Jupiter that is now also classified as a dwarf planet.

"I think [the IAU's definition] is going to collapse by 2015 when the Dawn mission gets to Ceres and the New Horizons mission gets to Pluto because we're not going to see irregular-shaped, impact crater-filled, boring surfaces. We're going to see dynamic worlds," Sykes said.

The IAU's decision also came under fire because only 4 percent of its scientists participated in the vote that reclassified Pluto. But Christensen said the IAU was following its statutes and bylaws and has passed other resolutions in a similar way.

The subject of Pluto didn't come up at the IAU's general assembly earlier this month in Rio de Janeiro, Brazil, Christensen added.
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Sykes countered that astronomers wanted to discuss the issue, just as they have at other recent major meetings, but the IAU didn't allow there to be any sessions on planet classification.

"I think the IAU did a terrible disservice to science, because it gives the public the impression that science is done by votes," Sykes said. "And that's not the way science is done at all." "<

posted in Astronomy - 0 replies

LCROSS peeks at the Earth and moon

idea1407 — Mon, 24 Aug 2009 20:06:10 GMT

http://www.nasa.gov/mission_pages/LCROSS/multimedia/EarthLookcont.html

>"More Images from the LCROSS Earth/Moon Look Calibration on Aug. 17, 2009"<

posted in Astronomy - 0 replies

Black Holes: The Other Side of Infinity

freetheweed — Sun, 23 Aug 2009 09:31:46 GMT

http://www.hulu.com/watch/14906/black-holes-the-other-side-of-infinity

Black Holes: The Other Side of Infinity

There are places where gravity is so powerful nothing can escape, where time and space literally crash into the abyss. Can you feel the pull? Narrated by Liam Neeson. 23 minutes

posted in Astronomy - 1 reply

Big Wave

idea1407 — Mon, 24 Aug 2009 19:37:52 GMT

http://www.space.com/scienceastronomy/090817-dark-energy-alternative.html
>"'Big Wave' Theory Offers Alternative to Dark Energy
By Clara Moskowitz
Staff Writer
posted: 17 August 2009
05:56 pm ET

This story was updated at 2:40 p.m. on Aug. 18.

Mathematicians have proposed an alternative explanation for the accelerating expansion of the universe that does not rely on the mystifying idea of dark energy.

According to the new proposition, the universe is not accelerating, as observations suggest. Instead, an expanding wave flowing through space-time has caused distant galaxies to appear to be accelerating away from us. This big wave, initiated after the Big Bang that is thought to have sparked the universe, could explain why objects today appear to be farther away from us than they should be according to the Standard Model of cosmology.

"We're saying that maybe the resulting expanding wave is actually causing the anomalous acceleration," said Blake Temple of the University of California, Davis. "We're saying that dark energy may not really be the correct explanation."

The researchers derived a set of equations describing expanding waves that fit Einstein's theory of general relativity, and which could also account for the apparent acceleration. Temple outlines the new idea with Joel Smoller of the University of Michigan in the Aug. 17 issue of the journal Proceedings of the National Academy of Sciences.

While more research will be needed to see if the idea holds up, "the research could change the way astronomers view the composition of our universe," according to a summary from the journal.

To convince other cosmologists, the new model will have to pass muster with further inquiry.

"There are many observational tests of the standard cosmological model that the proposed model must pass, aside from the late phase of accelerated expansion," said Avi Loeb, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics. "These include big bang nucleosynthesis, the quantitative details of the microwave background anisotropies, the Lyman-alpha forest, and galaxy surveys. The authors do not discuss how their model compares to these tests, and whether the number of free parameters they require in order to fit these observational constraints is smaller than in the standard model. Until they do so, it is not clear why this alternative model should be regarded as advantageous."

Johns Hopkins University astrophysicist Mario Livio agreed that to be seriously considered, the model must be able to predict properties of the universe that astronomers can measure.

He said the real test "is in whether they are able to reproduce all the observed cosmological parameters (as determined, e.g. by a combination of the Hubble Constant and the parameters determined by the CMB observations). To only produce an apparent acceleration is in itself interesting, but not particularly meaningful."

Inconvenient truths

Dark energy is itself a hasty fix to an inconvenient truth discovered by astronomers in the late 1990s: that the universe is expanding, and the rate of this expansion seems to be constantly picking up speed.

To explain this startling finding, cosmologists invoked dark energy, a hypothetical form of energy that is pulling the universe apart in all directions (note that dark energy is wholly separate from the equally mysterious concept of dark matter - a hypothetical form of matter that populates the universe, interacting gravitationally with normal matter, but which cannot be seen with light). In this interpretation, the whole universe is blowing up like a balloon, and from any given point within it, all distant objects appear to be speeding away from you.

But not everyone is happy with the dark energy explanation.

"It just seems like an unnatural correction to the equations - it's like a fudge factor," Temple told SPACE.com. "The equations don't make quite as much physical sense when you put it in. You just put it in to fit the data."

Temple and Smoller think the idea of an expanding wave makes more sense.

"At this stage we think this a very plausible theory," Temple said. "We're saying there isn't any acceleration. The galaxies are displaced from where they're supposed to be because we're in the aftermath of a wave that put those galaxies in a slightly different position."

Ripples in a pond

Temple compared the wave to what happens when you throw a rock into a pond. In this case, the rock would be the Big Bang, and the concentric ripples that result are like a series of waves throughout the universe. Later on, when the first galaxies start to form, they are forming inside space-time that has already been displaced from where it would have been without the wave. So when we observe these galaxies with telescopes, they don't appear to be where we would expect if there had never been a big wave.

One potential issue with this idea is that it might require a big coincidence.

For the universe to appear to be accelerating at the same rate in all directions, we in the Milky Way would have to be near a local center, at the spot where an expansion wave was initiated early in the Big Bang when the universe was filled with radiation.

Temple concedes that this is a coincidence, but said it's possible that we are merely in the center of a smaller wave that affects the galaxies we can see from our vantage point - we need not be in the center of the entire universe for the idea to work."<

posted in Astronomy - 0 replies

Star formation, Big Squeeze?

idea1407 — Fri, 21 Aug 2009 19:16:26 GMT

http://www.space.com/scienceastronomy/090821-stars-trigger.html

>"Big Squeeze Creates New Stars in Cosmic Cloud
By Clara Moskowitz
Staff Writer
posted: 21 August 2009
08:23 am ET

New photos of a cosmic cloud rich with young stars offer tantalizing clues about how those stars came to be.

Scientists recently combined images from the Chandra X-ray Observatory and the Spitzer Space Telescope to zoom in on the cosmic cloud Cepheus B, located in our galaxy about 2,400 light years from Earth.

This cloud of mostly hydrogen gas and dust contains a host of bright young stars whose birth could have been triggered by a nearby massive star outside the cloud. This star, called HD 217086, is bombarding the region with strong radiation. While this energetic flow is likely to have evaporated the cloud's outer layers, it also could have pushed a compression wave into the cloud that may have driven star formation by increasing the density of gas in the cloud's interior.

The new observations, which help astronomers estimate the ages of many of the young stars, support this model of star formation. "<

posted in Astronomy - 1 reply

Martian Meteorite Reveals Past Atmosphere

Hummingbird — Tue, 18 Aug 2009 15:46:06 GMT

http://scienceblogs.com/startswithabang/2009/08/a_meteorite_on_mars.php

From the article:

"Consideration of existing model results indicates a meteorite this size requires a thicker atmosphere," said rover team member Matt Golombek of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Either Mars has hidden reserves of carbon-dioxide ice that can supply large amounts of carbon-dioxide gas into the atmosphere during warm periods of more recent climate cycles, or Block Island fell billions of years ago."

posted in Astronomy - 0 replies

Nasa assembles Ares test rocket

freetheweed — Mon, 17 Aug 2009 11:08:55 GMT

http://news.bbc.co.uk/2/hi/science/nature/8204921.stm

Page last updated at 09:34 GMT, Monday, 17 August 2009 10:34 UK

NASA assembles Ares test rocket

The US space agency has completed the assembly of its Ares I-X rocket ahead of a test flight scheduled for October.

The Ares I rocket is a key component of Nasa's next-generation space transportation system.

The agency will use Ares I to launch the Orion capsule - the spacecraft to be used for human space missions after the space shuttle retires.

The unmanned test version of the rocket is standing in the vehicle assembly building (VAB) at Kennedy Space Center.

The final segments of the Ares I-X rocket, including the simulated crew module and launch abort system, were stacked together on 13 August on a mobile launcher platform at the VAB in Florida.

Nasa has released images, providing the first look at the 99m (327ft) launch vehicle.

The Ares I-X flight test is targeted for 31 October.

Nasa is scheduled to retire the space shuttle in 2010; the completed Ares-Orion system is not due to fly until 2015 at the earliest.

posted in Astronomy - 2 replies

US probe captures Saturn equinox

freetheweed — Sat, 15 Aug 2009 08:40:34 GMT

http://news.bbc.co.uk/2/hi/science/nature/8201595.stm

Page last updated at 14:10 GMT, Friday, 14 August 2009 15:10 UK

By Judith Burns
Science reporter, BBC News

Raw images of the moment Saturn reached its equinox have been beamed to Earth by the US Cassini spacecraft.

Scientists are studying the unprocessed pictures to uncover new discoveries in the gas giant's ring system.

Equinox is the moment when the Sun crosses a planet's equator, making day and night the same length.

During this time, the Sun's angle over Saturn is lowered, showing new objects and irregular structures as shadows on the otherwise flat plane of the rings.

Saturn's orbit is so vast that Equinox happens only once every 15 Earth years.

At the moment of equinox, the rings turn edge-on to the Sun and reflect almost no sunlight.

This is the first equinox since 1994 and the first time there has been an observer, in the shape of the joint US and European spacecraft, Cassini.

In an email, Dr Carolyn Porco, leader of Cassini's imaging team, said the long-awaited images did not disappoint: "Even a cursory examination of them reveals strange new phenomena we hadn't fully anticipated.

"Over the next week or two, the [Cassini] imaging team will be poring over these precious gems to see what other surprises await us, and, as usual, we will announce what we have found as soon as we can."

Cassini was launched in October 1997 from Florida's Cape Canaveral Air Force Station. It arrived at Saturn in July 2004 to embark on a four-year mission of exploration around the planet and its moons.

The spacecraft is still operating well and has been re-programmed to carry out new tasks. Its current mission is to answer some of the questions raised by its earlier observations.

posted in Astronomy - 4 replies

Kepler proves it can find planets and more

idea1407 — Wed, 12 Aug 2009 18:19:48 GMT

http://tribes.tribe.net/spacesciences/thread/26d15f4f-9a88-49d1-9e31-190fb297aa7d#876f0159-70f7-4937-85da-da9f1480602d

posted in Astronomy - 2 replies

Defying Gravity

freetheweed — Tue, 11 Aug 2009 12:55:58 GMT

A new show on ABC... thought y'all might like it. 3 episodes so far, here's the first:

http://www.hulu.com/watch/86722/defying-gravity-pilot#s-p1-so-i0

The Antares begins its mission to explore the planets in the solar system.

posted in Astronomy - 21 replies

Planet Smash-Up Sends Vaporized Rock, Hot Lava Flying

Serge — Wed, 12 Aug 2009 01:31:30 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

News release: 2009-119, August 10, 2009

PASADENA, Calif. -- NASA's Spitzer Space Telescope has found evidence of a high-speed collision between two burgeoning planets around a young star.

Astronomers say that two rocky bodies, one as least as big as our moon and the other at least as big as Mercury, slammed into each other within the last few thousand years or so -- not long ago by cosmic standards. The impact destroyed the smaller body, vaporizing huge amounts of rock and flinging massive plumes of hot lava into space. An artist's animation of the event is at http://www.nasa.gov/mission_pages/spitzer/multimedia/spitzer-20090810.html .

Spitzer's infrared detectors were able to pick up the signatures of the vaporized rock, along with pieces of refrozen lava, called tektites.

"This collision had to be huge and incredibly high-speed for rock to have been vaporized and melted," said Carey M. Lisse of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md., lead author of a new paper describing the findings in the Aug. 20 issue of the Astrophysical Journal. "This is a really rare and short-lived event, critical in the formation of Earth-like planets and moons. We're lucky to have witnessed one not long after it happened."

Lisse and his colleagues say the cosmic crash is similar to the one that formed our moon more than 4 billion years ago, when a body the size of Mars rammed into Earth.

"The collision that formed our moon would have been tremendous, enough to melt the surface of Earth," said co-author Geoff Bryden of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Debris from the collision most likely settled into a disk around Earth that eventually coalesced to make the moon. This is about the same scale of impact we're seeing with Spitzer -- we don't know if a moon will form or not, but we know a large rocky body's surface was red hot, warped and melted."

Our solar system's early history is rich with similar tales of destruction. Giant impacts are thought to have stripped Mercury of its outer crust, tipped Uranus on its side and spun Venus backward, to name a few examples. Such violence is a routine aspect of planet building. Rocky planets form and grow in size by colliding and sticking together, merging their cores and shedding some of their surfaces. Though things have settled down in our solar system today, impacts still occur, as was observed last month after a small space object crashed into Jupiter.

Lisse and his team observed a star called HD 172555, which is about 12 million years old and located about 100 light-years away in the far southern constellation Pavo, or the Peacock (for comparison, our solar system is 4.5 billion years old). The astronomers used an instrument on Spitzer, called a spectrograph, to break apart the star's light and look for fingerprints of chemicals, in what is called a spectrum. What they found was very strange. "I had never seen anything like this before," said Lisse. "The spectrum was very unusual."

After careful analysis, the researchers identified lots of amorphous silica, or essentially melted glass. Silica can be found on Earth in obsidian rocks and tektites. Obsidian is black, shiny volcanic glass. Tektites are hardened chunks of lava that are thought to form when meteorites hit Earth.

Large quantities of orbiting silicon monoxide gas were also detected, created when much of the rock was vaporized. In addition, the astronomers found rocky rubble that was probably flung out from the planetary wreck.

The mass of the dust and gas observed suggests the combined mass of the two charging bodies was more than twice that of our moon.

Their speed must have been tremendous as well -- the two bodies would have to have been traveling at a velocity relative to each other of at least 10 kilometers per second (about 22,400 miles per hour) before the collision.

Spitzer has witnessed the dusty aftermath of large asteroidal impacts before, but did not find evidence for the same type of violence -- melted and vaporized rock sprayed everywhere. Instead, large amounts of dust, gravel, and boulder-sized rubble were observed, indicating the collisions might have been slower-paced. "Almost all large impacts are like stately, slow-moving Titanic-versus-the-iceberg collisions, whereas this one must have been a huge fiery blast, over in the blink of an eye and full of fury," said Lisse.

Other authors include C.H. Chen of the Space Telescope Science Institute, Baltimore, Md.; M.C. Wyatt of the University of Cambridge, England; A. Morlok of the Open University, London, England; I. Song of The University of Georgia, Athens, Ga.; and P. Sheehan of the University of Rochester, N.Y.

JPL manages the Spitzer mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. Spitzer's infrared spectrograph, which made the observations in 2004 before the telescope began its "warm" mission, was built by Cornell University, Ithaca, N.Y. Its development was led by Jim Houck of Cornell.

For more information about Spitzer, visit http://www.spitzer.caltech.edu/spitzer and http://www.spitzer.caltech.edu/spitzer . More information about NASA's planet-finding program is at http://planetquest.jpl.nasa.gov .

From: subscription email

posted in Astronomy - 4 replies

Hubble Image of Jupiter Impact Site

Hummingbird — Sat, 25 Jul 2009 00:56:53 GMT

http://imgsrc.hubblesite.org/hu/db/images/hs-2009-23-b-full_jpg.jpg

Photo taken on 7/23/09

posted in Astronomy - 26 replies

LCROSS to launch and impact the moon

idea1407 — Mon, 27 Jul 2009 11:06:00 GMT

LCROSS is going to launch this week. *Fingers crossed* Its impact in the near future should be a great target for all yall astronomers.

LCROSS Science brief video - details the mission.

http://www.youtube.com/watch?v=4Y9GRFdercM

NASA page about the impact:
http://lcross.arc.nasa.gov/impact.htm

posted in Astronomy - 3 replies

Copyright Free Photos ???

Rocky — Fri, 03 Jul 2009 17:51:15 GMT

Where are the best places to find copyright free astronomy and archaeoastronomy (ancient stone observatories) photos???

posted in Astronomy - 4 replies

LRO Images of Apollo Landing Sites

Hummingbird — Sat, 18 Jul 2009 15:32:39 GMT

http://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/apollosites.html

posted in Astronomy - 6 replies

New Spot Discovered on Jupiter

Hummingbird — Mon, 20 Jul 2009 00:42:11 GMT

From the article:
"Amateur astronomer Anthony Wesley from Canberra, Australia captured an image of Jupiter on July 19 showing a possible new impact site. Anthony's image shows a new dark spot in the South Polar Region of Jupiter, at approximately 216° longitude in System 2. It looks very similar to the impact marks made on Jupiter when comet Shoemaker-Levy 9 crashed into the gas giant in 1994. (But read the Bad Astronomer's post that the black spot could also be weather.)"

http://www.universetoday.com/2009/07/19/possible-new-impact-on-jupiter/

posted in Astronomy - 7 replies

Now is the time to actually see the ISS!

iMosaicmix — Sun, 05 Jul 2009 03:06:25 GMT

http://spacefellowship.com/2009/07/04/space-station-marathon/

The International Space Station (ISS) is about to make a remarkable series of flybys over the United States. Beginning this 4th of July weekend, the station will appear once, twice, and sometimes three times a day for many days in a row. No matter where you live, you should have at least a few opportunities to see the biggest spaceship ever built.

posted in Astronomy - 4 replies

Watch.

Manjushri — Sat, 04 Jul 2009 02:15:22 GMT

http://stereo-ssc.nascom.nasa.gov/browse/2009/07/03/behind_20090703_cor2_512.mpg

posted in Astronomy - 35 replies

astronomy ≠ astrology

MickD — Tue, 14 Jul 2009 17:06:17 GMT

The head astronomer at my local observatory (Fernbank), says he routinely gets calls from people who ask if certain things will happen because the stars are in certain alignments.

I shouldn't be surprised by this, but I am surprised by this.

I am further surprised that he can patiently say to folks that astronomy is not astrology.

posted in Astronomy - 2 replies

Aldrin urges unity for Mars mission

freetheweed — Fri, 03 Jul 2009 08:23:41 GMT

Video at the link

http://news.bbc.co.uk/2/hi/programmes/newsnight/8131706.stmk

By Verity Murphy
BBC Newsnight

Apollo 11 moonwalker Buzz Aldrin says the world is at a crucial moment where decisive action from a global leader now would start humans on a path towards the colonisation of other planets:

"I happen to feel that at this juncture in time that a leader of the world of some nation has the opportunity to initiate a clear pathway that can result in creatures from the Earth beginning to settle on another planet in this solar system," he told the BBC's Newsnight programme.

And, perhaps surprisingly for a man who secured his place in the history of space exploration as a member of the crew which made the first lunar landing, he says that such action would be "far more a big deal than Kennedy saying we are going to compete with the Russians to go to the Moon".

It is 40 years this month since Aldrin joined Neil Armstrong on the Moon in the celebrated Apollo 11 mission - a mission which combined one of the most daring feats of exploration in human history with one of its most astonishing scientific achievements.

The world was left in awe of the technological prowess and ambition of Nasa and of its people - most particularly of Aldrin, Armstrong and Michael Collins - the men who actually rode atop the Saturn V rocket to the Moon.

The Apollo 11 landing was the culmination of a journey which began with US President John F Kennedy's 1961 announcement of the dramatic and ambitious goal of sending a US astronaut safely to the Moon before the end of the decade.

Return to the Moon

In 2004, another White House incumbent, President George W Bush outlined his vision for the future of US space travel and said that the US would "return to the Moon by 2020, as the launching point for missions beyond".

But the Space Shuttle programme which has been Nasa's crew transportation system since 1981, will come to an end next year when the last craft is retired.

And though Nasa is working on a replacement system, Constellation, this will not be introduced until 2014-15.

So for five years after the shuttle's retirement in 2010, US astronauts will be dependent on Russia to fly them into orbit on their space capsule, Soyuz.

Aldrin believes that the Constellation system - made up of the Orion capsule and its Ares launcher - cannot possibly be ready in time to meet Mr Bush's 2020 deadline.

"Building one crew rocket, which has difficulties, and one big rocket, which won't be ready until 2018, there is no way to get to the Moon by 2020."

'Wrong destination'

In fact Aldrin does not believe that the Moon should be Nasa's destination target at all - he has called instead for Nasa to refocus its efforts on Mars.

"It is the only other habitable planet," he told Newsnight. "We have sent many rovers there and we have found conditions there that I feel can be made suitable for human existence much easier than the Moon can."

"It is just further away," he added.

But Aldrin does not think this distance is insurmountable - using a "hop, skip and jump" method which he outlined in an article for Popular Mechanics in 2005, he believes we can travel to Mars by stopping off on its moon Phobos:

"We can go and visit that and occupy it for a year, year-and-a-half, and visit it three times before we go to the surface," he said. "It is a logical stopping off point."

Under Aldrin's plan Nasa should scrap the Ares capsule and have the Orion fly on a Delta IV or Atlas V to Mars.

Effects of recession

Key to such an epic voyage is, according to Aldrin, the US turning its back on its go-it-alone space exploration policy and instead galvanising support from other nations which have not been major contributors to the International Space Station (ISS), but which do have space programmes, such as China and India:

"The US needs to begin to chart a pathway and then we are going to find we need refuelling coming from other space craft, and for things to be sent ahead to the surface of Mars to help support the people, we need supplies to be sent there...

"We need unity of purpose and unity of leadership."

But is a recession-hit world really ready to contemplate a mission to Mars when the Apollo project, which saw Aldrin travel to the Moon in 1969 was ruinously expensive?

The latest occupant in the White House, President Barack Obama, has ordered a public review of Nasa's manned activities.

The White House's chief scientist, John Holdren, said at the time the Augustine Commission was ordered that "it would be only prudent" to review the human spaceflight programme given the scale of its ambition and "the significant investment of both funds and scientific capital".

When campaigning for the presidency, Mr Obama said that he believes that "Nasa needs an inspirational vision for the 21st Century".

"My vision will build on the great goals set forth in recent years, to maintain a robust programme of human space exploration and ensure the fulfilment of Nasa's mission."

Buzz Aldrin told Newsnight that he will be outlining his thoughts to the Augustine Commission when he returns to the US at the weekend - how closely his vision matches that of Mr Obama remains to be seen.

posted in Astronomy - 0 replies

Secrets of Space Blobs Revealed

Serge — Thu, 25 Jun 2009 18:06:25 GMT

By Clara Moskowitz
Staff Writer
posted: 24 June 2009
02:59 pm ET

Perplexing "blobs" of gas seen in the faraway universe are a bit more comprehensible thanks to a new study.

Glowing with an eerie brightness, the massive blobs, http://www.space.com/common/media/video/player.php?videoRef=SP_090624_Black-Hole , seem to surround very young galaxies, http://www.space.com/scienceastronomy/090428-st-young-galaxies.html . NASA's Chandra X-ray Observatory and other telescopes examined the distant gas balls and found that their luminosity is likely due to energy released by black holes and star formation inside the galaxies.

"For ten years the secrets of the blobs, http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=090624-two-blobs-02.jpg&cap=On+left%2C+a+blob+of+glowing+hydrogen+gas+appears+yellow.+On+right%2C+the+blue+light+is+evidence+for+a+growing+supermassive+black+hole+in+the+center+of+the+galaxy.+The+hydrogen+gas+appears+yellow.+Credit%3A+X-ray+(NASA%2FCXC%2FDurham+Univ.%2FD.Alexander+et+al.)%3B+Optical+(NASA%2FESA%2FSTScI%2FIoA%2FS.Chapman+et+al.)%3B+Lyman-alpha+Optical+(NAOJ%2FSubaru%2FTohoku+Univ.%2FT.Hayashino+et+al.)%3B+Infrared+(NASA%2FJPL-Caltech%2FDurham+Univ.%2FJ.Geach+et+al.) , had been buried from view, but now we've uncovered their power source," said James Geach of Durham University in the United Kingdom, who led the study. "Now we can settle some important arguments about what role they played in the original construction of galaxies and black holes."

Astronomers first spotted the blobs about a decade ago, but couldn't figure out much about them, such as how they formed or why they were glowing (hence the vague name "blob").

Recently Chandra, the Spitzer Space Telescope and other observatories pointed their lenses at a patch of space dubbed "SSA22", http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=090624-blobs-field-02.jpg&cap=An+optical+image+from+the+Subaru+telescope+of+the+SSA22+field+containing+strange+blobs+of+hydrogen+gas.+Credit%3A+NAOJ%2FSubaru%2FTohoku+Univ.%2FT.Hayashino+et+al. , where 29 of these huge reservoirs of hydrogen gas can be seen. The blobs in this field date from when the universe was only about 2 billion years old, or roughly 15 percent of its current age.

The observations revealed point-like sources of bright X-ray light - telltale signs of supermassive black holes, http://www.space.com/scienceastronomy/090608-aas-black-hole-masses.html , – within many of the blobs. They also showed that several of the baby galaxies within the gas clouds were dominated by robust star formation.

Astronomers say the radiation from the black holes and star formation could be providing the energy to light up the blobs.

It's possible that all massive galaxies go through a phase when they are surrounded by glowing clouds like this, Geach said. However, since that phase is relatively short-lived – perhaps only a few hundred million years – and occurs when the galaxy is very young, astronomers will have a hard time catching most galaxies at the right moment.

"Probably all galaxies go through this phase, but to start off with the gas is hard to detect 'cause there's nothing there to light it up," said Sir Martin Rees, an astronomer at the University of Cambridge who did not work on the new study. Once star formation gets going and the black holes begin emitting strong radiation, the blobs glow for a short period of time. "Then later the gas is either all converted into stars or blown away," he said.

The hydrogen gas making up the blobs is likely leftover material from when the galaxy formed that did not get pulled in to become stars. In fact, the galaxies probably exist in a sea of this leftover primordial gas, but only a small cocoon around them is lit up and visible to us, Geach said.

"There's still a lot to learn about these objects," said coauthor Bret Lehmer, also at Durham. "In the future we'll conduct wide-area hunts for these blobs."

Geach and team will report their findings in the July 10 issue of The Astrophysical Journal.

Video: Black Hole Powers Gaseous Blob - http://www.space.com/common/media/video/player.php?videoRef=BlackHoleBirthBurst

The Top 10 Weirdest Things in Space - http://www.space.com/scienceastronomy/top_10_weird.html

Original Publication: http://www.space.com/scienceastronomy/090624-early-universe.html

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Herschel telescope 'opens eyes'

freetheweed — Mon, 15 Jun 2009 09:23:38 GMT

http://news.bbc.co.uk/2/hi/science/nature/8099105.stm

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JPL Organizes Forum on Space-Mission Information Technology

Serge — Sat, 30 May 2009 13:26:24 GMT

Mark Petrovich 818-393-4359
Jet Propulsion Laboratory, Pasadena, Calif.
Mark.Petrovich@jpl.nasa.gov

TIP SHEET: 2009-091, May 28, 2009

WHAT: NASA's Jet Propulsion Laboratory in Pasadena, Calif., will co-organize the Third Annual International Conference on Space-Mission Challenges for Information Technology, to be held July 19 through 23 in Pasadena.

The conference, aimed at space-mission technology system designers, engineers, scientists and space explorers, will focus on current information-technology practice and challenges, as well as emerging information technologies. The Institute of Electrical and Electronics Engineers (IEEE), based in New York City, is officially sponsoring the conference.

Conference topics include:

· Human-robot interfaces

· Innovative Information Technology methods for rapid technology mission infusion

· Information Technology tools for risk management

· Autonomy -- rovers to operations

· Information Technology for the Interplanetary Internet and next-generation, space-based networking

· Spaceborne computing architectures

· Onboard vehicle health diagnosis and repair

Conference attendees may also participate in an event being held in conjunction--the International Workshop on Planning and Scheduling for Space. This workshop, the sixth in an annual series, will focus on the challenges and opportunities the planning and scheduling community faces when addressing the needs of a wide range of space-based applications.

WHEN: Sunday through Thursday, July 19 through 23

WHERE: Pasadena Convention Center, 300 E. Green Street, Pasadena, Calif. 91101

MORE INFO: Register online at http://smc-it.org . Early-bird registration ends June 15. Media who want to attend should RSVP to Mark Petrovich in the JPL Media Relations Office at 818-393-4359 or Mark.Petrovich@jpl.nasa.gov.

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NASA Selects Student's Entry as New Mars Rover Name

Serge — Wed, 27 May 2009 22:31:06 GMT

Alan Buis/Carolina Martinez 1-818-354-0474/9382
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov/carolina.martinez@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

NEWS RELEASE: 2009-089, May 27, 2009

PASADENA, Calif. – NASA's Mars Science Laboratory rover, scheduled for launch in 2011, has a new name, thanks to a sixth-grade student from Kansas. Twelve-year-old Clara Ma from the Sunflower Elementary school in Lenexa submitted the winning entry, "Curiosity." As her prize, Ma wins a trip to NASA's Jet Propulsion Laboratory in Pasadena, Calif., where she will be invited to sign her name directly onto the rover as it is being assembled.

A NASA panel selected the name following a nationwide student contest that attracted more than 9,000 proposals via the Internet and mail. The panel primarily took into account the quality of submitted essays. Name suggestions from the Mars Science Laboratory project leaders and a non-binding public poll also were considered.

"Students from every state suggested names for this rover. That's testimony to the excitement Mars missions spark in our next generation of explorers," said Mark Dahl, the mission's program executive at NASA Headquarters in Washington. "Many of the nominating essays were excellent and several of the names would have fit well. I am especially pleased with the choice, which recognizes something universally human and essential to science."

Ma decided to enter the rover-naming contest after she heard about it at her school.

"I was really interested in space, but I thought space was something I could only read about in books and look at during the night from so far away," Ma said. "I thought that I would never be able to get close to it, so for me, naming the Mars rover would at least be one step closer."

"Curiosity is an everlasting flame that burns in everyone's mind. It makes me get out of bed in the morning and wonder what surprises life will throw at me that day," Ma wrote in her winning essay. "Curiosity is such a powerful force. Without it, we wouldn't be who we are today. Curiosity is the passion that drives us through our everyday lives. We have become explorers and scientists with our need to ask questions and to wonder."

The naming contest was conducted in partnership with Disney-Pixar's animated film "WALL-E." The activity invited ideas from students 5 - 18 years old enrolled in a U.S. school. The contest started in November 2008. Entries were accepted until midnight Jan. 25.

Walt Disney Studios Motion Pictures supplied the prizes for the contest, including 30 for semifinalists related to "WALL-E." Nine finalists have been invited to provide messages to be placed on a microchip mounted on Curiosity. The microchip also will contain the names of thousands of people around the world who have "signed" their names electronically via the Internet. Additional electronic signatures still are being accepted via the Internet.

"We have been eager to call the rover by name," said Pete Theisinger, who manages the JPL team building and testing Curiosity. "Giving it a name worthy of this mission's quest means a lot to the people working on it."

Curiosity will be larger and more capable than any craft previously sent to land on the Red Planet. It will check to see whether the environment in a selected landing region ever has been favorable for supporting microbial life and preserving evidence of life. The rover also will search for minerals that formed in the presence of water and look for several chemical building blocks of life.

The Mars Science Laboratory project is managed by JPL for NASA's Science Mission Directorate in Washington.

For more information about the mission and the contest winner, visit:
http://www.nasa.gov/msl .

To send your name on the rover microchip, visit: http://marsprogram.jpl.nasa.gov/msl/participate/sendyourname .

JPL is managed for NASA by the California Institute of Technology in Pasadena.

-end-

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Herschel and Planck on Way to Study our Cosmic Roots

Serge — Thu, 14 May 2009 23:46:34 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Whitney.clavin@jpl.nasa.gov

NEWS RELEASE: 2009-085, May 14, 2009

The Herschel and Planck spacecraft successfully blasted into space at 6:12 a.m. Pacific Time (9:12 a.m. Eastern Time) on May 14 from the Guiana Space Centre in French Guiana.

The European Space Agency missions, with significant participation from NASA, hitched a ride together on an Ariane 5 rocket, but now have different journeys before them. Herschel will explore, with unprecedented clarity, the earliest stages of star and galaxy birth in the universe; it will help answer the question of how our sun and Milky Way galaxy came to be. Planck will look back to almost the beginning of time itself, gathering new details to help explain how our universe came to be.

"These two missions have spent a lot of time together," said Ulf Israelsson, NASA project manager for both Herschel and Planck at NASA's Jet Propulsion Laboratory, Pasadena , Calif. "But now they are going their separate ways, each ready to do what it does best."

JPL contributed key technology to both missions. NASA team members will play an important role in data analysis and science operations.

Herschel separated from its Ariane 5 rocket 26 minutes after launch, followed by Planck about two minutes later. The spacecraft are traveling on separate trajectories to a point in the Earth-sun system called the second Lagrangian point, four times farther away than the moon's orbit, or an average distance of 1.5 million kilometers (930,000 miles) from Earth. They will spend the rest of their missions independently orbiting this point -- located on the other side of Earth from the sun -- as they make their way around the sun every year. See animations at http://www.esa.int/esa-mmg/mmg.pl?b=b&type=VA&mission=Herschel&single=y&start=10 and http://www.esa.int/esa-mmg/mmg.pl?b=b&type=VA&mission=Planck&single=y&start=10 .

Herschel will start preparing for science operations while en route toward its operational orbit, which will be reached in about two months. Four months later, the science mission will begin and is expected to last more than three-and-a-half years. Planck will reach a similar orbit in roughly two months, with science observations beginning one month later. The mission's science operations are scheduled to last a minimum of 15 months, with the possibility of an extension.

Both observatories are designed to see light that our human eyes cannot. Herschel will detect light that has gone largely unexplored until now, with wavelengths in the infrared and submillimeter range. It will make the most detailed measurements yet of the cold and dark wombs where the embryos of stars and galaxies have just begun to grow.

Herschel will also be able to detect key elements and molecules involved in a star's life, tracing their evolution from atoms to potentially life-forming materials. One of these molecules is water; astronomers say Herschel will provide a greatly improved measurement of how much water there is in space.

"Using Herschel is like opening a dirty window and getting a clear view of stars and galaxies," said Paul Goldsmith, the NASA Herschel project scientist at JPL.

Planck will see longer wavelength light, from the submillimeter to microwave range. It will work like the ultimate time capsule, to see light that has traveled billions of years from the newborn universe to reach us. This light, called the cosmic microwave background, contains information about the Big Bang that created space and time itself.

"Our previous images of the baby universe were like fuzzy snapshots -- now we'll have the cleanest, deepest and sharpest images ever made of the early universe," said Charles Lawrence, the NASA Planck project scientist at JPL.

In order to do their jobs, the instruments on both spacecrafts will be icy cold. Liquid helium will cool the coldest of Herschel's detectors to just 0.3 Kelvin (minus 459 degrees Fahrenheit), or 0.3 degrees above the coldest temperature theoretically attainable in the universe. Planck's coldest detectors, which are chilled by cutting-edge coolers developed in part by JPL, will reach a frosty 0.1 Kelvin.

Herschel is a European Space Agency mission, with science instruments provided by a consortium of European-led institutes, and with important participation by NASA. NASA's Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA. More information is online at http://www.nasa.gov/herschel and http://www.herschel.caltech.edu/ and http://www.esa.int/herschel .

Planck is a European Space Agency mission, with significant participation from NASA. NASA's Planck Project Office is based at JPL. JPL contributed mission-enabling technology for both of Planck's science instruments. European, U.S. and NASA Planck scientists will work together to analyze the Planck data. More information is online at http://www.nasa.gov/planck and http://www.esa.int/planck .

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Let the Planet Hunt Begin

Serge — Wed, 13 May 2009 22:26:55 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Whitney.clavin@jpl.nasa.gov

Michael Mewhinney 650-604-3937
NASA's Ames Research Center, Moffett Field, Calif.
michael.s.mewhinney@nasa.gov

Kepler Mission Status Report , May 13, 2009

NASA's Kepler spacecraft has begun its search for other Earth-like worlds. The mission, which launched from Cape Canaveral, Fla., on March 6, will spend the next three-and-a-half years staring at more than 100,000 stars for telltale signs of planets. Kepler has the unique ability to find planets as small as Earth that orbit sun-like stars at distances where temperatures are right for possible lakes and oceans.

"Now the fun begins," said William Borucki, Kepler science principal investigator at NASA's Ames Research Center, Moffett Field, Calif. "We are all really excited to start sorting through the data and discovering the planets."

Scientists and engineers have spent the last two months checking out and calibrating the Kepler spacecraft. Data have been collected to characterize the imaging performance as well as the noise level in the measurement electronics. The scientists have constructed the list of targets for the start of the planet search, and this information has been loaded onto the spacecraft.

"If Kepler got into a staring contest, it would win," said James Fanson, Kepler project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "The spacecraft is ready to stare intently at the same stars for several years so that it can precisely measure the slightest changes in their brightness caused by planets." Kepler will hunt for planets by looking for periodic dips in the brightness of stars -- events that occur when orbiting planets cross in front of their stars and partially block the light.

The mission's first finds are expected to be large, gas planets situated close to their stars. Such discoveries could be announced as early as next year.

Kepler is a NASA Discovery mission. NASA Ames Research Center, Moffett Field, Calif., is the home organization of the science principal investigator, and is responsible for the ground system development, mission operations and science data analysis. JPL manages the Kepler mission development. Ball Aerospace & Technologies Corp. of Boulder, Colo., is responsible for developing the Kepler flight system and supporting mission operations.

For more information about the Kepler mission, visit:
http://www.nasa.gov/kepler and http://www.kepler.nasa.gov .

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#2009-084

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Spitzer Catches Star Cooking Up Comet Crystals

Serge — Wed, 13 May 2009 22:23:33 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
Whitney.clavin@jpl.nasa.gov

NEWS RELEASE: 2009-083, May 13, 2009

Scientists have long wondered how tiny silicate crystals, which need sizzling high temperatures to form, have found their way into frozen comets, born in the deep freeze of the solar system's outer edges. The crystals would have begun as non-crystallized silicate particles, part of the mix of gas and dust from which the solar system developed.

A team of astronomers believes they have found a new explanation for both where and how these crystals may have been created, by using NASA's Spitzer Space Telescope to observe the growing pains of a young, sun-like star. Their study results, which appear in the May 14 issue of Nature, provide new insight into the formation of planets and comets.

The researchers from Germany, Hungary and the Netherlands found that silicate appears to have been transformed into crystalline form by an outburst from a star. They detected the infrared signature of silicate crystals on the disk of dust and gas surrounding the star EX Lupi during one of its frequent flare-ups, or outbursts, seen by Spitzer in April 2008. These crystals were not present in Spitzer's previous observations of the star's disk during one of its quiet periods.

"We believe that we have observed, for the first time, ongoing crystal formation," said one of the paper's authors, Attila Juhasz of the Max-Planck Institute for Astronomy in Heidelberg, Germany. "We think that the crystals were formed by thermal annealing of small particles on the surface layer of the star's inner disk by heat from the outburst. This is a completely new scenario about how this material could be created."

Annealing is a process in which a material is heated to a certain temperature at which some of its bonds break and then re-form, changing the material's physical properties. It is one way that silicate dust can be transformed into crystalline form.

Scientists previously had considered two different possible scenarios in which annealing could create the silicate crystals found in comets and young stars' disks. In one scenario, long exposure to heat from an infant star might anneal some of the silicate dust inside the disk's center. In the other, shock waves induced by a large body within the disk might heat dust grains suddenly to the right temperature to crystallize them, after which the crystals would cool nearly as quickly.

What Juhasz and his colleagues found at EX Lupi didn't fit either of the earlier theories. "We concluded that this is a third way in which silicate crystals may be formed with annealing, one not considered before," said the paper's lead author, Peter Abraham of the Hungarian Academy of Sciences' Konkoly Observatory, Budapest, Hungary.

EX Lupi is a young star, possibly similar to our sun four or five billion years ago. Every few years, it experiences outbursts, or eruptions, that astronomers think are the result of the star gathering up mass that has accumulated in its surrounding disk. These flare-ups vary in intensity, with really big eruptions occurring every 50 years or so.

The researchers observed EX Lupi with Spitzer's infrared spectrograph in April 2008. Although the star was beginning to fade from the peak of a major outburst detected in January, it was still 30 times brighter than when it was quiet. When they compared this new view of the erupting star with Spitzer measurements made in 2005 before the eruption began, they found significant changes.

In 2005, the silicate on the surface of the star's disk appeared to be in the form of amorphous grains of dust. In 2008, the spectrum showed the presence of crystalline silicate on top of amorphous dust. The crystals appear to be forsterite, a material often found in comets and in protoplanetary disks. The crystals also appear hot, evidence that they were created in a high-temperature process, but not by shock heating. If that were the case, they would already be cool.

"At outburst, EX Lupi became about 100 times more luminous," said Juhasz. "Crystals formed in the surface layer of the disk but just at the distance from the star where the temperature was high enough to anneal the silicate--about 1,000 Kelvin (1,340 degrees Fahrenheit)--but still lower than 1,500 Kelvin (2,240 degrees Fahrenheit). Above that, the dust grains will evaporate." The radius of this crystal formation zone, the researchers note, is comparable to that of the terrestrial-planet region in the solar system.

"These observations show, for the first time, the actual production of crystalline silicates like those found in comets and meteorites in our own solar system," said Spitzer Project Scientist Michael Werner of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "So what we see in comets today may have been produced by repeated bursts of energy when the sun was young."

JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information about Spitzer is at http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer .

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Hubble Photographs a Planetary Nebula to Commemorate Decommissioning of Super Camera

Serge — Wed, 13 May 2009 22:16:44 GMT

DC Agle 818-393-9011
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
agle@jpl.nasa.gov

JD Harrington/Dwayne Brown
NASA Headquarters, Washington
202-358-5241/1726
j.d.harrington@nasa.gov /dwayne.c.brown@nasa.gov

Cheryl Gundy 410-338-4707
Space Telescope Science Institute, Baltimore, Md.
gundy@stsci.edu

News release: 2009-081, May 10, 2009

The Hubble community bids farewell to the soon-to-be decommissioned Wide Field and Planetary Camera 2 onboard NASA's Hubble Space Telescope. In tribute to Hubble's longest-running optical camera, which was developed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif., a planetary nebula has been imaged as the camera’s final "pretty picture."

This planetary nebula is known as Kohoutek 4-55 (or K 4-55). It is one of a series of planetary nebulae that were named after their discoverer, Czech astronomer Lubos Kohoutek. A planetary nebula contains the outer layers of a red giant star that were expelled into interstellar space when the star was in the late stages of its life. Ultraviolet radiation emitted from the remaining hot core of the star ionizes the ejected gas shells, causing them to glow.

In the specific case of K 4-55, a bright inner ring is surrounded by a bipolar structure. The entire system is then surrounded by a faint red halo, seen in the emission by nitrogen gas. This multi-shell structure is fairly uncommon in planetary nebulae.

This Hubble image was taken by the Wide Field and Planetary Camera 2 on May 4, 2009. The colors represent the makeup of the various emission clouds in the nebula: red represents nitrogen, green represents hydrogen, and blue represents oxygen. K 4-55 is nearly 4,600 light-years away in the constellation Cygnus.

The Wide Field and Planetary Camera 2 instrument, which was installed in 1993 to replace the original Wide Field/Planetary Camera, will be removed to make room for Wide Field Camera 3 during the upcoming Hubble Servicing Mission.

During the camera's amazing, nearly 16-year run, the Wide Field and Planetary Camera 2 provided outstanding science and spectacular images of the cosmos. Some of its best-remembered images are of the Eagle Nebula pillars, Comet P/Shoemaker-Levy 9's impacts on Jupiter's atmosphere, and the 1995 Hubble Deep Field -- the longest and deepest Hubble optical image of its time.

The scientific and inspirational legacy of the camera will be felt by astronomers and the public alike, for as long as the story of the Hubble Space Telescope is told.

For images and more information about planetary nebula K 4-55, visit: http://hubblesite.org/news/2009/21 .

For more information about the Wide Field and Planetary Camera 2, visit: http://www.jpl.nasa.gov/wfpc2/ .

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency and is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The Space Telescope Science Institute conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc., Washington, D.C.

The Space Telescope Science Institute is an International Year of Astronomy 2009 program partner. JPL is managed for NASA by the California Institute of Technology in Pasadena.

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Stellarium?

Pineapple2 — Tue, 12 May 2009 03:21:33 GMT

I have been using a freeware program, "Stellarium" I downloaded from www.stellarium.org , for months now. I actually prefer the older version than the one online now. Are there any better freeware virtual planetarium programs that you know of? Thanks

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If Spitzer Could Talk: An Interview with NASA's Coolest Space Telescope

Serge — Wed, 06 May 2009 14:47:50 GMT

Feature,
May 4, 2009

NASA's Spitzer Space Telescope is about to use its last drop of the coolant that has chilled it for the past five-and-a-half years. On about May 12, give or take a week or so, the observatory is predicted to run out of the liquid helium that has run through its veins, keeping its infrared detectors at frosty operating temperatures of just a few degrees above the coldest temperature possible, called absolute zero.

The spacecraft, which is now in orbit around the sun more than 100-million kilometers (62-million miles) behind Earth, will heat up just a bit -- its instruments will warm up from - 456 degrees Fahrenheit (-271 Celsius) to - 404 degrees Fahrenheit (-242 Celsius). This is still way colder than an ice cube, which is about 32 degrees Fahrenheit. More importantly, it is still cold enough for some of Spitzer's infrared detectors to keep on probing the cosmos for at least two more years.

If Spitzer could talk, here's how an interview with the observatory might go:

Interviewer: It's cold in here.

Spitzer: Sorry. Even though I'm warming up, I still need to be quite chilly for two of my infrared channels to continue working.

Interviewer: Why do infrared telescopes need to be cold?

Spitzer: Good question. Infrared light is produced by heat. So, engineers reduce my own heat to make sure that I'm measuring just the infrared light from the objects I'm studying. This is the same reason why I circle around the sun, far behind Earth, and why I have big sun shields -- to keep cool.

Interviewer: Tell me, Spitzer, about what you consider to be your greatest discovery?

Spitzer: Probably my work on exoplanets, which are planets that orbit stars other than our sun. I hate to brag, but I was the first telescope to see actual light from an exoplanet. I was also the first to split that light up into a spectrum. Oh, sorry, there I go again with the techie talk. Light is made up of lots of different wavelengths in the same way that a rainbow is made up of different colors. I was able to split an exoplanet's light up into its various infrared wavelengths. This spectral information teaches us about planets' atmospheres.

Interviewer: What did you learn about the planets?

Spitzer: For one thing, I learned that the hot gas exoplanets, called "hot Jupiters," are not all alike. Some are wild, with temperatures as hot as fire and almost as cold as ice. Others are more even-keeled. I also created the first temperature map of an exoplanet, and watched a storm of colossal proportions brewing across the face of one bizarre exoplanet – it has an orbit that swings in really close to its star and then back out to about where Earth sits in our solar system.

Interviewer: You seem to really like planets.

Spitzer: Well, you know, I wasn't even originally designed to see exoplanets! It was a complete surprise to me that I had this amazing ability. I can tell you that I do, and always will, have a thing for planetary disks. Because I have infrared eyes, I can see the warm and dusty planetary materials that swirl in disks around young stars. I can also see older disks littered with the remnants of planets. In fact, I've probably looked at thousands of disks so far. What's been fun is finding them around all sorts of oddball stars, such as those that are dead, doubled up as twins and even as small as planets. Bottom line is that the process of growing planets seems to happen quite easily all over the galaxy, and perhaps the universe.

Interviewer: Does that mean aliens could be everywhere?

Spitzer: I can't really give you a good answer for that. Yes, the studies of disks are showing us that rocky planets are common, but we don't know if the planets could have life. Also, keep in mind that, as of now, nobody has detected any planets that are just like Earth. These would be rocky worlds around stars like our sun that have the right temperature for lakes and oceans. That job will most likely fall to NASA's Kepler mission, which will begin hunting for them soon.

Interviewer: Did you look at other objects besides disks and planets?

Spitzer: Oh yes, certainly. I have looked at comets in our solar system, the farthest galaxies known, and everything in-between. I was really excited to find hundreds of hidden black holes billions of light-years away. Astronomers had known they were there because they shoot X-rays into space that can be detected as a diffuse glow. But the objects themselves were choked in dust. My infrared eyes, unlike your human eyes, can see through dust, so I was able to round up a lot of these missing black holes.

Interviewer: Is there any other discovery you want to mention?

Spitzer: There are too many to list, but I am particularly proud of this huge mosaic I took of a large swath of our Milky Way galaxy. It looks stunning when you print it out to poster size, and it's the best view ever of the bustling central portion of our galaxy. You see, the middle of the Milky Way is hopping with stars and dust. It's chaos, and visible-light cannot escape. These observations not only look cool, they also helped astronomers remap the structure of our galaxy. The new map shows just two spiral arms of stars instead of four as previously believed. How crazy is that!

Interviewer: So what lies ahead?

Spitzer: Well, I'm really looking forward to the warm mission, because now that I have just two infrared channels working, I have more time to look at larger chunks of space for longer periods of time. I can help astronomers answer some really important "big picture" questions, which we didn't have time for before.

Interviewer: Can you list some specific projects you'll be working on?

Spitzer: I plan to continue studying exoplanets, including new "hot Jupiters" that Kepler is expected to find. I will also refine estimates of the rate at which our local universe, or space, is expanding. And I will stare at the very distant universe, trying to see some of the farthest objects possible. Oh, and I am also going to survey thousands of asteroids in our neck of the solar system, and get the first real estimate of their size distribution. This will tell us approximately how often big asteroids might come close to Earth.

Interviewer: That sounds scary.

Spitzer: Actually, this information will help us prepare for them. And NASA tracks near-Earth objects diligently. More information can only help.

Interviewer: Will you still take the pretty pictures?

Spitzer: You think my pictures are pretty? Thank you! Yes, I will still snap a lot of pictures. For instance, I will continue to probe cloudy star-forming regions in our galaxy, which often make dramatic pictures.

Interviewer: Anything else you'd like to add?

Spitzer: My cool years have been more than I could ask for, and I look forward to more adventures to come. I'd also like to thank all of the scientists and engineers who have worked so hard to make my mission an ongoing success. And, if any of my fans out there want more info, they can go to www.spitzer.caltech.edu/spitzer .

-end-

From: subscription email

posted in Astronomy - 1 reply

NASA Releases Interactive 3-D Views of Space Station, New Mars Rover

Serge — Sat, 09 May 2009 14:18:29 GMT

Guy Webster 1-818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Michael Mewhinney 1-650-604-3937
Ames Research Center, Moffett Field, Calif.
michael.s.mewhinney@nasa.gov

John Yembrick 1-202-358-1100
Headquarters, Washington
john.yembrick-1@nasa.gov

News release: 2009-080, May 7, 2009

PASADENA, Calif. -- NASA released an interactive, 3-D photographic collection of internal and external views of the International Space Station and a model of the next Mars rover on Thursday, May 7.

NASA and Microsoft's Virtual Earth team developed the online experience with hundreds of photographs and Microsoft’s photo imaging technology called Photosynth. Using a click-and-drag interface, viewers can zoom in to see details of the space station's modules and solar arrays or zoom out for a more global view of the complex.

"Photosynth brings the public closer to our spaceflight equipment and hardware," said Bill Gerstenmaier, associate administrator for Space Operations at NASA Headquarters in Washington. "The space station pictures are not simulations or graphic representations but actual images taken recently by astronauts while in orbit. Although you're not flying 220 miles above the Earth at 17,500 miles an hour, it allows you to navigate and view amazing details of the real station as though you were there."

The software uses photographs from standard digital cameras to construct a 3-D view that can be navigated and explored online.

"This stunning collection of photographs using Microsoft's Photosynth interactive 3-D imaging technology provides people around the world with an exciting new way to explore the space station and learn about NASA’s upcoming Mars Science Laboratory mission," said S. Pete Worden, director of NASA's Ames Research Center in Moffett Field, Calif. "This collaboration with Microsoft offers the public the opportunity to participate in future exploration using this innovative technology."

The Mars rover imagery gives viewers an opportunity to preview the hardware of NASA's Mars Science Laboratory, currently being assembled for launch to the Red Planet in 2011.

"We are making this enhanced viewing experience available from the Mars Science Laboratory project because we're eager for the public to share in the excitement that's building for this mission," said Fuk Li, manager of NASA's Mars Exploration Program at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

NASA's Photosynth collection can be viewed at http://www.nasa.gov/photosynth .

The NASA images also can be viewed on Microsoft’s Virtual Earth Web site at http://www.microsoft.com/virtualearth .

While roaming through different components of the station, the public also can join in a scavenger hunt. NASA has a list of items that can be found in the Photosynth collection. These items include a station crew patch, a spacesuit and a bell that is traditionally used to announce the arrival of a visiting spacecraft. Clues to help in the hunt will be posted on NASA’s Facebook page and @NASA on Twitter. To access these sites, visit http://www.nasa.gov/collaborate .

NASA astronaut Sandra Magnus took the internal images of the space station during the 129 days she lived aboard the complex. She photographed the station’s exterior while aboard the space shuttle Discovery, which flew her back to Earth in March. The rover images were taken of a full-scale model in a Mars-simulation testing area at JPL. Photosynth has multiple potential benefits for NASA. Engineers can use it to examine hardware, and astronauts can use it for space station familiarization training.

Photosynth software allows the combination of up to thousands of regular digital photos of a scene to present a detailed 3-D model of a subject, giving viewers the sensation of smoothly gliding around the scene from every angle. A collection can be constructed using photos from a single source or multiple sources. The NASA Photosynth collection also includes shuttle Endeavour preparing for its STS-118 mission in August 2008.

For more information about the space station, visit http://www.nasa.gov/station . For more information about the Mars Science Laboratory, visit http://mars.jpl.nasa.gov/msl . JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington.

-end-

From: subscription email

posted in Astronomy - 0 replies

Why we shouldn't hide our problems from ET

Serge — Sat, 18 Apr 2009 13:32:44 GMT

03:29, 18 April 2009
by Douglas Vakoch

For nearly 50 years, the Search for Extraterrestrial Intelligence (SETI) has scanned the heavens with radio telescopes for signs of alien technology. At the same time, scientists have painstakingly crafted messages to send in reply. When NASA launched its Voyager missions in 1977, for example, both spacecraft carried audio recordings depicting the diversity of life and culture on Earth (see gallery - http://www.newscientist.com/gallery/dn16980-messaging-et ).

But never have those messages truly represented all of humanity. On 15 May that will change as the SETI Institute launches a project to collect messages from people around the world, http://messages.seti.org/ . Though there are currently no plans to transmit these messages into space, the project aims to foster a global discussion about whether we should send more than symbolic messages to the stars, and if so, what we should say.

The standard wisdom in interstellar diplomacy is to avoid controversy – a sometimes elusive goal. In the early 1970s, NASA attached plaques to two Pioneer spacecraft etched with basic mathematics, science and line drawings of a man and woman. Some complained the space agency was sending "smut into space", with the naked figures revealing more than they deemed proper for a first encounter.

Other messages have escaped such criticism. One from the Arecibo Observatory in Puerto Rico depicts the human form in so few pixels that its sex is not clear. The Voyager recordings excluded war, poverty and disease.

However, a comprehensive message to the stars should not shrink from the details. Might not an advanced extraterrestrial species, savvy in the ways of intelligent being, notice that something was missing from our description of ourselves? An acknowledgment of our flaws and frailties seems a more honest approach than sending a sanitised, one-sided story. Honesty is a good starting point for a conversation that could last for generations.

Douglas Vakoch, director of interstellar message composition at the SETI Institute in Mountain View, California, says any future messages sent to ET should reflect the human race as it really is – warts and all.

"One of the standard assumptions [about composing messages] is we should talk about what we all have in common; we should avoid controversy," he says. "My concern is that if we do that, our messages may be pretty brief and pretty boring."

If we continue to dodge controversy, we risk sending messages that are both brief and boring. We sometimes clash in our beliefs and customs; we disagree over matters of taste and morality. In no small part this diversity of perspectives is what characterises us as a species. And it may just make us intriguing enough to the inhabitants of other worlds to elicit a reply.

*Douglas Vakoch is director of interstellar message composition at the SETI Institute in Mountain View, California

Original Story:

http://www.newscientist.com/article/dn16981-why-we-shouldnt-hide-our-problems-from-et.html?DCMP=OTC-rss&nsref=space

and

http://www.newscientist.com/article/dn16980-what-voyagers-golden-record-tells-et-about-earth.html?DCMP=OTC-rss&nsref=space

posted in Astronomy - 9 replies

Galileo

ergonaut — Tue, 05 May 2009 18:11:17 GMT

I just returned to Canada yesterday after visiting Italy. While I was in Firenze I visited the Galileo Exibition that is on there for the International Year of Astronomy 2009. The exhibition was touted as 'Images of the Universe From Antiquity to the Telescope.' Happy 400th birthday to the telescope!

"The exhibition is a journey through space and time, exploring the science of the heavens and the birth of astronomy from the astonishing knowledge of the heavenly bodies that the peoples of Mesopotamia and the Nile delta had built up to the achievements of the classical Greek and Roman civilizations and of the Islamic, medieval Christian and Renaissance cultures. Finally, it takes us to the head of the astronomical revolution heralded by Nicolaus Copernicus, confirmed by Galileo and his telescope, and completed by such extraordinary figures as Johannes Kepler, René Descartes and Isaac Newton." from http://www.imss.fi.it/news/emostra_galileo_imm_universo.html

Featured were ancient gold and bronze astrolabes and the complex mechanical models commissioned by Ptolemy, Aristotle, and Copernicus to depict the theories of the motion of the sun and planets, and Galileo's written apopogy to the Church for refuting their view by agreeing with the Copernican view of a sun centered solar system. Galileo's telescopes were there as were telescopes made by his contempories. Also there for viewing were Galileo's controvercial drawings of the Moon, Sun, Jupiter, and Saturn. An added bonus was there inside of a glass bell jar - Galileo's index finger!

If you find yourself in Florence this summer I recommend you make the time to visit the man (his finger anyway) that invented modern astronomy, or for that matter, modern science!

posted in Astronomy - 1 reply

Good Place To Look Up The TNO'S?

Sat, 25 Apr 2009 21:40:04 GMT

Where would an amature astronomer find information about when they were discovered, thier orbits - and other information?

posted in Astronomy - 2 replies

Galaxies and Your Morning Coffee

Hummingbird — Tue, 21 Apr 2009 16:20:50 GMT

http://www.sciencedaily.com/releases/2009/04/090414160801.htm

posted in Astronomy - 0 replies

NASA's Kepler Captures First Views of Planet-Hunting Territory

Serge — Thu, 16 Apr 2009 20:21:29 GMT

Whitney Clavin 818-354-4673
Jet Propulsion Laboratory, Pasadena, Calif.
whitney.clavin@jpl.nasa.gov

J.D. Harrington 202-358-5241
Headquarters, Washington
j.d.harrington@nasa.gov

Michael Mewhinney 650-604-3937
Ames Research Center, Moffett Field, Calif.
michael.s.mewhinney@nasa.gov

News release: 2009-068, April 16, 2009

PASADENA, Calif. -- NASA's Kepler mission has taken its first images of the star-rich sky where it will soon begin hunting for planets like Earth.

The new "first light" images show the mission's target patch of sky, a vast starry field in the Cygnus-Lyra region of our Milky Way galaxy. One image shows millions of stars in Kepler's full field of view, while two others zoom in on portions of the larger region. The images can be seen online at:

http://www.nasa.gov/mission_pages/kepler/multimedia/20090416.html

"Kepler's first glimpse of the sky is awe-inspiring," said Lia LaPiana, Kepler's program executive at NASA Headquarters in Washington. "To be able to see millions of stars in a single snapshot is simply breathtaking."

One new image from Kepler shows its entire field of view -- a 100-square-degree portion of the sky, equivalent to two side-by-side dips of the Big Dipper. The regions contain an estimated 14 millions stars, more than 100,000 of which were selected as ideal candidates for planet hunting.

Two other views focus on just one-thousandth of the full field of view. In one image, a cluster of stars located about 13,000 light-years from Earth, called NGC 6791, can be seen in the lower left corner. The other image zooms in on a region containing a star, called Tres-2, with a known Jupiter-like planet orbiting every 2.5 days.

"It's thrilling to see this treasure trove of stars," said William Borucki, science principal investigator for Kepler at NASA's Ames Research Center at Moffett Field, Calif. "We expect to find hundreds of planets circling those stars, and for the first time, we can look for Earth-size planets in the habitable zones around other stars like the sun."

Kepler will spend the next three-and-a-half years searching more than 100,000 pre-selected stars for signs of planets. It is expected to find a variety of worlds, from large, gaseous ones, to rocky ones as small as Earth. The mission is the first with the ability to find planets like ours -- small, rocky planets orbiting sun-like stars in the habitable zone, where temperatures are right for possible lakes and oceans of water.

To find the planets, Kepler will stare at one large expanse of sky for the duration of its lifetime, looking for periodic dips in starlight that occur as planets circle in front of their stars and partially block the light. Its 95-megapixel camera, the largest ever launched into space, can detect tiny changes in a star's brightness of only 20 parts per million. Images from the camera are intentionally blurred to minimize the number of bright stars that saturate the detectors. While some of the slightly saturated stars are candidates for planet searches, heavily saturated stars are not.

"Everything about Kepler has been optimized to find Earth-size planets," said James Fanson, Kepler's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our images are road maps that will allow us, in a few years, to point to a star and say a world like ours is there."

Scientists and engineers will spend the next few weeks calibrating Kepler's science instrument, the photometer, and adjusting the telescope's alignment to achieve the best focus. Once these steps are complete, the planet hunt will begin.

"We've spent years designing this mission, so actually being able to see through its eyes is tremendously exciting," said Eric Bachtell, the lead Kepler systems engineer at Ball Aerospace & Technology Corp. in Boulder, Colo. Bachtell has been working on the design, development and testing of Kepler for nine years.

Kepler is a NASA Discovery mission. Ames is responsible for the ground system development, mission operations and science data analysis. JPL manages the Kepler mission development. Ball Aerospace & Technologies Corp. is responsible for developing the Kepler flight system and supporting mission operations.

For images, animations and more information about the Kepler mission, visit:

http://www.nasa.gov/kepler

-end-

From: subscription email

posted in Astronomy - 2 replies

Black Hole Creates Spectacular Light Show

Serge — Tue, 14 Apr 2009 19:48:14 GMT

By Clara Moskowitz
Staff Writer
posted: 14 April 2009
12:37 pm ET

A jet of gas spewing from a huge black hole has mysteriously brightened, flaring to 90 times its normal glow.

For seven years the Hubble Space Telescope has been watching the jet, which pours out of the supermassive black hole, http://www.space.com/common/media/video/player.php?videoRef=080428_blazar-coil , in the center of the M87 galaxy. It has photographed the strange phenomenon, http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=090414-jet-flare-02.jpg&cap=In+these+Hubble+photos%2C+the+core+of+M87+is+located+at+lower+left+in+the+images.+HST-1+is+the+bright+blob+at+center.+The+glowing+material+at+far+right+is+part+of+a+stream+of+particles+in+the+jet+that+speed+up+and+glow+in+the+ultraviolet.+The+photos+show+show+the+jet+growing+brighter+over+a+seven-year+period.+Credit%3A+NASA%2C+ESA%2C+and+J.+Madrid+(McMaster+University) , fading and then brightening, with a peak that even outshines M87's brilliant core.

Scientists have dubbed the enigmatic bright blob HST-1, and are so far at a loss to explain its weird behavior.

"I did not expect the jet in M87 or any other jet powered by accretion onto a black hole, http://www.space.com/scienceastronomy/blackhole_mw_040401.html , to increase in brightness in the way that this jet does," said astronomer Juan Madrid of McMaster University in Hamilton, Ontario, who conducted the Hubble study. "It grew 90 times brighter than normal. But the question is, does this happen to every single jet or active nucleus, or are we seeing some odd behavior from M87?"

Many supermassive black holes have jets of material, http://www.space.com/scienceastronomy/080428-mm-black-hole-blazar.html , that spray out perpendicularly from the donut-shaped ring of matter falling onto the black hole. These beams of hot gas are thought to result from magnetic field lines, http://www.space.com/scienceastronomy/060621_bhole_magnetic.html , that are twisted by the black hole's mass, and propel charged particles outward.

But most rays do not appear to blaze up with such extreme intensity as HST-1. Scientists aren't sure if it is an exceptional case, or if it represents a normal event for black hole jets, which are still not very well understood. In this case, the bright knot of HST-1 is about 214 light-years from the M87 galaxy's core

To learn more about this bizarre light show, Madrid analyzed the seven years' worth of Hubble images of the jet in ultraviolet light to capture changes in HST-1's behavior over time. He also compared the Hubble data to photos of the jet taken in X-rays by the Chandra X-ray Observatory and in radio by other telescopes.

Madrid found that between 1999 and 2005, the blob continually brightened. By May 2005, HST-1 was 90 times brighter than it was in 1999. After that, it seemed to fade, and then intensified again in November 2006.

"By watching the outburst over several years, I was able to follow the brightness and see the evolution of the flare over time," Madrid says. "We are lucky to have telescopes like Hubble and Chandra, because without them we would see the increase in brightness in the core of M87, but we would not know where it was coming from."

More data will be needed to solve the mystery of why HST-1 acts the way it does.

"We hope the observations will yield some theories that will give us some good explanations as to the mechanism that is causing the flaring," Madrid says. "Astronomers would like to know if this is an intrinsic instability of the jet when it plows its way out of the galaxy, or if it is something else."

This strange case could provide a unique opportunity to learn more about black hole jets in distant galaxies, which are difficult to study because they are so far away. M87 is located 54 million light-years away in the Virgo Cluster.

Madrid's study is detailed in the April 2009 issue of the Astronomical Journal.

Original Story: http://www.space.com/scienceastronomy/090414-jet-flare.html

posted in Astronomy - 2 replies

The Search for the Solar System's Lost Planet

Serge — Tue, 14 Apr 2009 20:14:55 GMT

By Clara Moskowitz
Staff Writer
posted: 13 April 2009
09:42 am ET

The solar system might once have had another planet named Theia, which may have helped create our own planet's moon.

Now two spacecraft are heading out to search for leftovers from this rumored sibling, http://www.space.com/scienceastronomy/moon_formation_040621.html , which would have been destroyed when the solar system was still young.

"It's a hypothetical world. We've never actually seen it, but some researchers believe it existed 4.5 billion years ago — and that it collided with Earth to form the moon, http://www.space.com/scienceastronomy/solarsystem/moon_making_010815-1.html ," said Mike Kaiser, a NASA scientist at the Goddard Space Flight Center in Maryland.

Theia is thought to have been about Mars-sized. If the planet crashed into Earth, http://www.space.com/scienceastronomy/planetearth/moonwhack_main_000901.html , long ago, debris from the collision could have clumped together to form the moon. This scenario was first conceived by Princeton scientists Edward Belbruno and Richard Gott.

Many researchers now figure that indeed some large object crashed into Earth, and the resulting debris coalesced to form the moon. It is unclear though if that colliding object was a planet, asteroid or comet.

In any case, the debris that would have spun out from the two slamming bodies would have mixed together, and could explain some aspects of the moon's geology, such as the size of the moon's core and the density and composition of moon rocks.

Scientists are hoping NASA's twin STEREO probes, launched in 2006, will be able to discover leftover traces of Theia that may finally help close the case on the birth of our moon.

So far, signs of Theia have proved elusive to telescopes searching from Earth. But the STEREO spacecraft are set to enter special points in space, called Lagrangian points, where the gravity from the Earth and the sun combine to form wells that tend to collect solar system detritus. [Click here for an animation that explains Lagrangian points - http://www.space.com/php/popup/lagrange/lagrange3.html .]

"The STEREO probes are entering these regions of space now," Kaiser, a STEREO project scientist, said. "This puts us in a good position to search for Theia's asteroid-sized leftovers."

By visiting the Lagrangian points directly, STEREO will be able to hunt for Theia chunks up close. The nearest approach to the bottoms of the gravitational wells will come in September and October 2009.

"STEREO is a solar observatory," Kaiser said. "The two probes are flanking the sun on opposite sides to gain a 3-D view of solar activity. We just happen to be passing through the L4 and L5 Lagrange points en route. This is purely bonus science."

Scientists think Theia may even have formed in one of these gravitational points of balance from the accumulation of flotsam that had built up there.

"Computer models show that Theia could have grown large enough to produce the moon if it formed in the L4 or L5 [Lagrangian] regions, where the balance of forces allowed enough material to accumulate," Kaiser said. "Later, Theia would have been nudged out of L4 or L5 by the increasing gravity of other developing planets like Venus and sent on a collision course with Earth."

24 Hours of Chaos: The Day The Moon Was Made - http://www.space.com/scienceastronomy/solarsystem/moon_making_010815-1.html

Top 10 Cool Moon Facts - http://www.space.com/scienceastronomy/top_10_cool_moon_facts-1.html

Editor's Note: This story was updated at 1:50 p.m. ET to properly credit Edward Belbruno and Richard Gott with the idea that a planet like Theia might have impacted Earth to form the moon.

Original Story: http://www.space.com/scienceastronomy/090413-mm-stereo-lagrange.html

posted in Astronomy - 3 replies

Black Holes Caught in Tug-of-War

Serge — Tue, 07 Apr 2009 00:26:07 GMT

By Jeremy Hsu
Staff Writer
posted: 06 April 2009
10:28 am ET

Supermassive black holes that pack the heft of billions of suns have the capacity to regulate their energy during a tug-of-war with a hot radiation wind that blows in from their debris disks.

Now 10 years worth of observations from the Chandra X-ray Observatory have uncovered the first clear evidence of this mysterious phenomenon occurring in a small black hole just 14 times the mass of the sun.

"The supermassive black hole, http://www.space.com/common/media/video/player.php?videoRef=080409-3_Black-holes , has thousands of stars nearby, a whole galaxy of matter to push around," said Joseph Nielson, an astrophysicist at the Harvard University. "So it's more like supermassive black holes have more opportunity to self-regulate."

The difficult patient

Black holes are so powerful that matter and even light cannot get out once trapped. But around black holes, a flurry of activity creates high-energy radiation — including radio waves and X-rays — that does flow out into space. Sometimes it all gets pretty messy, and some of the energy can be channeled into focused jets that shoot out in both direction along the axis of the black hole's rotation.

Chandra has kept an eye on a notoriously unpredictable black hole, http://www.space.com/common/media/video/player.php?videoRef=black_holes , that has 14 states of varying brightness, including a "heartbeat" state where periodic spikes in brightness resemble an EKG reading on a heart monitor.

Those unknown fluttering states have complicated observations of the GRS 1915+105 system for more than two decades, even though every major ground and space observatory has taken a peek at one time or another.

"These light curves are so bizarre that the black hole has been described as 'pathological,'" Nielson told SPACE.com "So the fact that we can see past all that, to the fundamental physics of winds and jets, is very exciting."

Most black holes ordinarily have long periods of quiet followed by occasional outbursts of jets and other activity, and so GRS 1915 is not unusual in that respect. But the small and feisty black hole does stand out by having had active outbursts for 17 years.

On and off again

The black hole's energy jet, http://www.space.com/common/media/video/player.php?videoRef=080428_blazar-coil , continually fights a seesaw battle with the hot radiation wind, as revealed in Chandra's X-ray observations. That wind flows in from the hot inner regions of the dusty, gaseous accretion disk surrounding the black hole.

"The outer disk actually absorbs some of that energy, and essentially begins to evaporate," Nielson said. "As it flows away from the disk, it absorbs even more of that radiation and its momentum, until the wind attains speeds of 1000 km/s [621 mi/s] or more."

Evaporation of the outer disk deprives the black hole jet of the mass that serves as its fuel, and eventually chokes it off. But the jets start up again. How the jets start up again remains a mystery.

Scientists know more about possible mechanisms driving the hot wind, which can include factors beyond the thermal driving or X-ray heating in the case of GRS 1915. Magnetic fields can also drive such winds around small black holes, also known as micro-quasars.

"So our paper kind of raises a new mystery, http://www.space.com/bestimg/?cat=strangest : why do some micro-quasars produce magnetically-driven winds and others produce thermally-driven winds?" Nielson noted. "Right now, we just don't know the answer."

An ongoing enigma

In any case, the jet appearances can also differ greatly in terms of how long they keep going.

"Maybe it's just for a few hours, but it could be for days or weeks," Nielson noted. "And some day, it will stop altogether -- no jets, no winds, just a quiet accretion disk slowly feeding the black hole."

But for now, GRS 1915 continues to provide useful information that researchers can apply to understanding its super-massive black hole cousins, which can defy observation for timescale reasons. An hour-long change in the small black hole would be equivalent to a timescale of 10,000 years in a super-massive black hole, if the latter weighed a billion times the mass of the sun.

Much more Chandra data also remains for just this one black hole, and researchers have yet to analyze it all.

"It's sort of like going back to see what's on each puzzle piece," Nielson said. "Chandra is great for this sort of thing, and we've got lots of data to pore over."

Original Story: http://www.space.com/scienceastronomy/090406-mm-black-hole.html

posted in Astronomy - 12 replies

Astronomers Help Solve Mystery Of Starlight's Origins Using A Telescope And Huge Balloon

Serge — Thu, 09 Apr 2009 06:18:06 GMT

ScienceDaily (Apr. 9, 2009) —

Scientists from the University of Toronto and the University of British Columbia have helped unveil the birthplaces of ancient stars using a two-tonne telescope carried by a balloon the size of a 33-storey building.

After two years spent analyzing data from the Balloon-borne Large-Aperture Sub-millimeter Telescope (BLAST) project, an international group of astronomers and astrophysicists from Canada, the U.S. and the U.K. reveals April 8 in the journal Nature that half of the starlight of the Universe comes from young, star-forming galaxies several billion light years away.

"While those familiar optical images of the night sky contain many fascinating and beautiful objects, they are missing half of the picture in describing the cosmic history of star formation," says UBC Astronomy Prof. Douglas Scott.

"Stars are born in clouds of gas and dust," says Barth Netterfield, a cosmologist in the Department of Astronomy & Astrophysics at U of T. "The dust absorbs the starlight, hiding the young stars from view. The brightest stars in the Universe are also the shortest lived and many never leave their stellar nursery. However, the warmed dust emits light at far-infrared and submillimetre wavelengths – invisible to the human eye, but visible to the sensitive thermo-detectors on BLAST."

"The history of star formation in the universe is written out in our data. It is beautiful. And it is just a taste of things to come," says UBC Prof. Mark Halpern, part of the UBC team that also includes post-doctoral fellows Ed Chapin and Gaelen Marsden.

In the 1990s, NASA's COBE satellite discovered a nearly uniform glow of submillimetre light, known as the Far Infrared Background. It had been expected that this radiation was coming from warmed dust enshrouding bright young stars, but the nature of the galaxies which contain the dust had remained a mystery.

The Nature study combines BLAST submillimetre observations at wavelengths around 0.3 mm – between infrared and microwave wavelengths – with data at much shorter infrared wavelengths from NASA's Spitzer Space Telescope to confirm that all of the Far Infrared Background comes from individual distant galaxies, answering a decade-old question of the radiation's origin.

In addition to leading the data analysis, the Canadian scientists also constructed much of the hardware that made BLAST a reality. The aluminum gondola was designed to protect the telescope, the onboard computers and data upon landing. The motorized pointing system controlled the 2,000 kilogram payload with its two-metre-in-diameter telescope – the largest of its kind – to one one-hundredth of a degree in precision. The complex electronics monitored and recorded nearly 1,000 sensors while the software – nearly 300,000 lines of code – controlled the payload during its long flight 39 kilometres above the Earth.

Flying the telescope above much of the atmosphere allowed the BLAST team to peer out into the distant Universe at wavelengths nearly unattainable from the ground, and uncover dust-enshrouded galaxies that hide about half of the starlight in the Universe.

"Over the last decade, submillimetre telescopes on the ground have produced several 'black and white' images no larger than the size of a fingernail at the end of your outstretched arm," says Chapin. "In a single 11-day flight BLAST has taken a huge leap forward, producing colour images the size of your hand."

BLAST has acted as a pathfinder for the SPIRE (Spectral and Photometric Imaging Receiver) instrument on the upcoming Herschel satellite, in which Canadians are also involved. Using the same detectors as SPIRE, BLAST has provided an invaluable first look at the submillimetre sky.

"BLAST has given us a new view of the Universe," says Netterfield, whose U of T colleagues on the project include department chair Peter G. Martin and graduate students Marco P. Viero, Donald V. Wiebe (now a post-doc at UBC) and Enzo Pascale (now a faculty member at Cardiff University). "The data we collected enable us to make discoveries in topics ranging from the formation of stars to the evolution of distant galaxies."

BLAST is also uniquely capable of studying the earliest stages of star formation locally, in the Milky Way Galaxy. The BLAST collaboration is also releasing a study, submitted to the Astrophysical Journal, of the largest survey to date of the earliest stages of star formation. This study documents the existence of a large population of cold clouds of gas and dust, many of which have cooled to less than -260 C. These cold cores, which exist for millions of years, are the birthplaces of stars.

"Over the last nine years, I've followed BLAST from Vancouver to Toronto, Philadelphia, New Mexico, Texas, northern Sweden and Antarctica, and it feels great for us to finally announce the results," says Marsden. "These results are a very big step forward in submillimetre astronomy."

"The world-leading scientific success of Canadian graduate students and post-docs working on BLAST has been very impressive and, speaking as an educator, very gratifying," says Halpern.

Collaborators on the BLAST project include: Mark Devlin, Jeff Klein, Marie Rex, Christopher Semisch and Matthew D. P. Truch (University of Pennsylvania); Mark Halpern, Edward L. Chapin, Gaelen Marsden, Henry Ngo and Douglas Scott (University of British Columbia); C. Barth Netterfield, Peter G. Martin, Marco P. Viero, Donald V. Wiebe (University of Toronto); Enzo Pascale, Peter A. R. Ade, Matthew Griffin, Peter C. Hargrave, Philip Mauskopf, Lorenzo Moncelsi and Carole Tucker (Cardiff University); James J. Bock (Jet Propulsion Laboratory); Gregory S. Tucker (Brown University); Itziar Aretxaga and David H. Hughes (Instituto Nacional de Astrofısica Optica y Electronica, Mexico); Joshua O. Gundersen and Nicholas Thomas (University of Miami); Luca Olmi (University of Puerto Rico, Rio Piedras Campus and the INAF), and Guillaume Patanchon (Laboratoire APC, Paris).

The BLAST experiment has been supported by funding from the National Aeronautics and Space Administration, the National Science Foundation Office of Polar Programs, the Canadian Space Agency, the Natural Sciences and Engineering Research Council of Canada, and the UK Science and Technology Facilities Council, and with assistance from Benjamin Magnelli, WestGrid computing resources and the SIMBAD and NASA/IPAC databases, the Columbia Scientific Balloon Facility, Ken Borek Air Ltd., and the mountaineers of McMurdo Station, Antarctica.

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Journal reference:

1.Devlin et al. Over half of the far-infrared background light comes from galaxies at z greater than or equal to 1.2. Nature, 2009; 458 (7239): 737 DOI: 10.1038/nature07918 - http://www.nature.com/nature/journal/v458/n7239/full/nature07918.html
Adapted from materials provided by University of British Columbia, http://www.ubc.ca/ .

Original Story: http://www.sciencedaily.com/releases/2009/04/090408145342.htm

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