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January 12, 2011, 6:36 PM CT

Most distant galaxy cluster

Most distant galaxy cluster
Caption: Members of the developing cluster COSMOS-AzTEC3 are shown here, circled in white, in this image taken by Japan's Subaru telescope atop Mauna Kea in Hawaii. The other dots in this picture are stars or galaxies that are not members of the cluster -- most of them are located closer to us than the cluster, but some are farther away. The two brightest spots are stars. Though they appear bright in this image, they are actually tens of thousands of times fainter than what we can see with our eyes.

Credit: Subaru, NASA, JPL-Caltech.

Bahram Mobasher, a professor of physics and astronomy at the University of California, Riverside, is a member of an international team of astronomers that has uncovered a burgeoning galactic metropolis, the most distant known in the early universe. This ancient collection of galaxies presumably grew into a modern galaxy cluster similar to the massive ones seen today.

The developing cluster, named COSMOS-AzTEC3, was discovered and characterized by multi-wavelength telescopes, including NASA's Spitzer, Chandra and Hubble space telescopes, and the ground-based W.M. Keck Observatory and Japan's Subaru Telescope.

"This is a galaxy cluster in the process of formation � a proto-cluster � more than 12 billion years ago," Mobasher said. "This proto-cluster was formed about one billion years after the Big Bang. Study of such structures reveals how galaxies came together and merged to form larger galaxies".

In the research project, Mobasher helped to identify member galaxies of this cluster and measure their distances and velocities. He also calculated when the proto-cluster was formed. To measure the spectra of candidates in the cluster, he secured observing time on the Keck Telescope in Hawaii.

Study results appear in the Jan. 13 issue of Nature........

Posted by: Brooke      Read more         Source


December 16, 2010, 7:42 AM CT

Meteorite just one piece of an unknown celestial body

Meteorite just one piece of an unknown celestial body
cientists from all over the world are taking a second, more expansive, look at the car-sized asteroid that exploded over Sudan's Nubian Desert in 2008. Initial research was focused on classifying the meteorite fragments that were collected two to five months after they were strewn across the desert and tracked by NASA's Near Earth Object astronomical network. Now in a series of 20 papers for a special double issue of the journal Meteoritics and Planetary Science, published on December 15, scientists have expanded their work to demonstrate the diversity of these fragments, with major implications for the meteorite's origin.

In the first round of research, Carnegie Geophysical scientist Doug Rumble, in collaboration with Muawia Shaddad of the University of Khartoum, examined one fragment of the asteroid, called 2008 TC3, and determined that it fell into a very rare category of meteorite called ureilites. Ureilites have a very different composition from most other meteorites. It has been suggested that all members of this meteoric family might have originated from the same source, called the ureilite parent body, which could have been a proto-planet.

Now Rumble has expanded his work to examine 11 meteorite fragments, focusing on the presence of oxygen isotopes. Isotopes are atoms of the same element that have extra neutrons in their nuclei.........

Posted by: Brooke      Read more         Source


December 9, 2010, 7:53 AM CT

Fourth planet in giant version of our solar system

Fourth planet in giant version of our solar system
Schematic representation of the HR8799 system compared to our own solar system, showing the four HR8799 planets and Jupiter, Saturn, Uranus and Neptune in our solar system. Infrared observations made by space telescopes have shown that the HR8799 system has a massive, dusty asteroid belt, thousands of times more dense than our own, that is gravitationally shaped by HR8799e the same way Jupiter shapes our asteroid belt, and an outer belt of cometary debris similar to, but much more massive, than our own Kuiper belt.
Credit: NRC-HIA, Christian Marois, and the W.M. Keck Observatory
Astronomers have discovered a fourth giant planet, joining three others that, in 2008, were the subject of the first-ever pictures of a planetary system orbiting another star other than our sun.

The solar system, discovered by a team from Lawrence Livermore National Laboratory and the National Research Council of Canada (NRC) Herzberg Institute of Astrophysics with collaborators at University of California, Los Angeles and Lowell Observatory, orbits around a dusty young star named HR8799, which is 129 light years away. All four planets are roughly five to seven times the mass of Jupiter.

Now, the same research team has discovered a fourth planet that is about seven times the mass of Jupiter. Using high-contrast, near infrared adaptive optics on the Keck II telescope in Hawaii, the astronomers imaged the fourth planet (dubbed HR8799e) in 2009 and confirmed its existence and orbit in 2010. The research appears in the Dec. 8 edition of the journal Nature.

"The images of this new inner planet in the system is the culmination of 10 years worth of innovation, making steady progress to optimize every observation and analysis step to allow the detection of planets located ever closer to their stars," said Christian Marois, a former LLNL postdoc now at NRC, and first author of the new paper.........

Posted by: Brooke      Read more         Source


November 11, 2010, 7:30 AM CT

Primordial Dry Ice Fuels Comet Jets

Primordial Dry Ice Fuels Comet Jets
Jets Galore

This enhanced image, one of the closest taken of comet Hartley 2.
One of the biggest comet findings coming out of the amazing images and data taken by the University of Maryland-led EPOXI mission as it zipped past comet Hartley 2 last week is that dry ice is the 'jet' fuel for this comet and perhaps a number of others.

Images from the flyby show spectacular jets of gas and particles bursting from a number of distinct spots on the surface of the comet. This is the first time images of a comet have been sharp enough to allow researchers to link jets of dust and gas with specific surface features. Analysis of the spectral signatures of the materials coming from the jets shows primarily CO2 gas (carbon dioxide) and particles of dust and ice.

"Previously it was thought that water vapor from water ice was the propulsive force behind jets of material coming off of the body, or nucleus, of the comet," said University of Maryland Astronomy Professor Jessica Sunshine, who is deputy principal investigator for the EPOXI mission. "We now have unambiguous evidence that solar heating of subsurface frozen carbon dioxide (dry ice), directly to a gas, a process known as sublimation, is powering the a number of jets of material coming from the comet. This is a finding that only could have been made by traveling to a comet, because ground based telescopes can't detect CO2 and current space telescopes aren't tuned to look for this gas," Sunshine said.........

Posted by: Brooke      Read more         Source


November 9, 2010, 10:43 PM CT

Giant Structure in our Galaxy

Giant Structure in our Galaxy
NASA's Fermi Gamma-ray Space Telescope has unveiled a previously unseen structure centered in the Milky Way. The feature spans 50,000 light-years and appears to be the remnant of an eruption from a supersized black hole at the center of our galaxy.

"What we see are two gamma-ray-emitting bubbles that extend 25,000 light-years north and south of the galactic center," said Doug Finkbeiner, an astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., who first recognized the feature. "We don't fully understand their nature or origin".

The structure spans more than half of the visible sky, from the constellation Virgo to the constellation Grus, and it appears to be millions of years old. A paper about the findings has been accepted for publication in The Astrophysical Journal.

Finkbeiner and his team discovered the bubbles by processing publicly available data from Fermi's Large Area Telescope (LAT). The LAT is the most sensitive and highest-resolution gamma-ray detector ever launched. Gamma rays are the highest-energy form of light.

Other astronomers studying gamma rays hadn't detected the bubbles partly because of a fog of gamma rays that appears throughout the sky. The fog happens when particles moving near the speed of light interact with light and interstellar gas in the Milky Way. The LAT team constantly refines models to uncover new gamma-ray sources obscured by this so-called diffuse emission. By using various estimates of the fog, Finkbeiner and colleagues were able to isolate it from the LAT data and unveil the giant bubbles.........

Posted by: Brooke      Read more         Source


October 8, 2010, 8:05 AM CT

Water discovered on second asteroid

Water discovered on second asteroid
Two teams of researchers who made national headlines in April for showing the first evidence of water ice and organic molecules on an asteroid have now discovered that asteroid 65 Cybele contains the same material.

Credit: Gabriel Perez, Instituto de Astrofisica de Canarias, Spain

Water ice on asteroids appears to be more common than expected, as per a newly released study that will be presented today at the world's largest gathering of planetary scientists.

Two teams of scientists who made national headlines in April for showing the first evidence of water ice and organic molecules on an asteroid have now discovered that asteroid 65 Cybele contains the same material.

"This discovery suggests that this region of our solar system contains more water ice than anticipated," said University of Central Florida Professor Humberto Campins. "And it supports the theory that asteroids may have hit Earth and brought our planet its water and the building blocks for life to form and evolve here."

Campins will present the teams' findings during the 42nd-annual Division of Planetary Sciences Conference (http://dps.aas.org/meetings/2010) in Pasadena, Calif., which concludes Oct. 8.

Asteroid 65 Cybele is somewhat larger than asteroid 24 Themis the subject of the teams' first paper. Cybele has a diameter of 290 km (180 miles). Themis has a diameter of 200 km (124 miles). Both are in the same region of the asteroid belt between Mars and Jupiter.

The academic article reporting this new finding has been accepted for publication in the European Journal "Astronomy and Astrophysics."........

Posted by: Brooke      Read more         Source


October 6, 2010, 7:46 AM CT

How sun steals Martian atmosphere

How sun steals Martian atmosphere
This is an artist's conception of the MAVEN spacecraft orbiting Mars.

Credit: NASA/Goddard Space Flight Center

The Red Planet bleeds. Not blood, but its atmosphere, slowly trickling away to space. The culprit is our sun, which is using its own breath, the solar wind, and its radiation to rob Mars of its air. The crime may have condemned the planet's surface, once apparently promising for life, to a cold and sterile existence.

Features on Mars resembling dry riverbeds, and the discovery of minerals that form in the presence of water, indicate that Mars once had a thicker atmosphere and was warm enough for liquid water to flow on the surface. However, somehow that thick atmosphere got lost in space. It appears Mars has been cold and dry for billions of years, with an atmosphere so thin, any liquid water on the surface quickly boils away while the sun's ultraviolet radiation scours the ground.

Such harsh conditions are the end of the road for known forms of life. Eventhough it's possible that martian life went underground, where liquid water may still exist and radiation can't reach.

The lead suspect for the theft is the sun, and its favorite M.O. appears to be the solar wind. All planets in our solar system are constantly blasted by the solar wind, a thin stream of electrically charged gas that continuously blows from the sun's surface into space. On Earth, our planet's global magnetic field shields our atmosphere by diverting most of the solar wind around it. The solar wind's electrically charged particles, ions and electrons, have difficulty crossing magnetic fields.........

Posted by: Brooke      Read more         Source


October 5, 2010, 7:22 AM CT

Europa's hidden ice chemistry

Europa's hidden ice chemistry
The icy surface of Europa is shown strewn with cracks, ridges and "chaotic terrain," where the surface has been disrupted and ice blocks have moved around. New laboratory experiments show that water ice and frozen sulfur dioxide react even at the frigid temperatures of Europa. Because the reaction occurs without the aid of radiation, it could take place throughout the moon's thick ice layer -- an outcome that would revamp current thinking about the chemistry and geology of this moon and perhaps others.

Credit: NASA/JPL/University of Arizona

The frigid ice of Jupiter's moon Europa appears to be hiding more than a presumed ocean: it is likely the scene of some unexpectedly fast chemistry between water and sulfur dioxide at extremely cold temperatures. Eventhough these molecules react easily as liquidsthey are well-known ingredients of acid rainMark Loeffler and Reggie Hudson at NASA's Goddard Space Flight Center in Greenbelt, Md., now report that they react as ices with surprising speed and high yield at temperatures hundreds of degrees below freezing. Because the reaction occurs without the aid of radiation, it could take place throughout Europa's thick coating of icean outcome that would revamp current thinking about the chemistry and geology of this moon and perhaps others.

"When people talk about chemistry on Europa, they typically talk about reactions that are driven by radiation," says Goddard scientist Mark Loeffler, the first author on the paper being published Oct. 2 in Geophysical Research Letters. That's because the moon's temperature hovers around 86 to 130 Kelvin, or about � to � F. In this extreme cold, most chemical reactions require an infusion of energy from radiation or light. On Europa, the energy comes from particles from Jupiter's radiation belts. Because most of those particles penetrate just fractions of an inch into the surface, models of Europa's chemistry typically stop there.........

Posted by: Brooke      Read more         Source


September 25, 2010, 9:30 AM CT

3-D computer simulations for supernovae explosions

3-D computer simulations for supernovae explosions
To simulate this supernova, the scientists used powerful supercomputers to employ a representation in three dimensions that allowed the various multidimensional instabilities to be expressed.
For scientists, supernovae are true superstars -- massive explosions of huge, dying stars that shine light on the shape and fate of the universe.

For a brief burst of time, supernovae can radiate more energy than the sun will emit in its lifetime. With the potential energy of 25 hundred trillion trillion nuclear weapons, they can outshine entire galaxies, producing some of the biggest explosions ever seen, and helping track distances across the cosmos.

Now, a Princeton-led team has found a way to make computer simulations of supernovae exploding in three dimensions, which may lead to new scientific insights.

Even though these mammoth explosions have been observed for thousands of years, for the past 50 years scientists have struggled to mimic the step-by-step destructive action on computers. Scientists argue that such simulations, even crude ones, are important, as they can lead to new information about the universe and help address this longstanding problem in astrophysics.

The new 3-D simulations are based on the idea that the collapsing star itself is not sphere-like, but distinctly asymmetrical and affected by a host of instabilities in the volatile mix surrounding its core.

"I think this is a big jump in our understanding of how these things can explode," said Adam Burrows, a professor of astrophysical sciences at Princeton, who led the research. "In principle, if you could go inside the supernovae to their centers, this is what you might see".........

Posted by: Brooke      Read more         Source


November 12, 2009, 6:09 PM CT

Weather the Trials of Orbit

Weather the Trials of Orbit
Space Shuttle Atlantis will next week carry a new Rensselaer nanomaterials experiment to the International Space Station. Samples of novel nanocomposite materials, seen in the photo, will be mounted to the hull of the space station, and tested to see how they weather the perils of space.
Novel nanomaterials developed at Rensselaer Polytechnic Institute are scheduled to blast off into orbit on November 16 aboard Space Shuttle Atlantis.

The project, funded by the U.S. Air Force Multi University Research Initiative (MURI), seeks to test the performance of the new nanocomposites in orbit. Space Shuttle Atlantis will carry the samples to the International Space Station (ISS). The materials will then be mounted to the station's outer hull in a Passive Experiment Carrier (PEC), and exposed to the rigors of space.

Rensselaer professors Linda Schadler, of the Department of Materials Science and Engineering, and Thierry Blanchet, of the Department of Mechanical, Aerospace, and Nuclear Engineering, worked with a team of scientists from the University of Florida to develop two different types of experimental nanomaterials. The MURI project and the University of Florida research team are led by Rensselaer alumnus W. Greg Sawyer '99, who earned his bachelor's, master's, and doctoral degrees from Rensselaer and is now the N. C. Ebaugh Professor of Mechanical and Aerospace Engineering at the University of Florida. Blanchet was Sawyer's doctoral adviser.

The first new material is a wear-resistant, low-friction nanocomposite, created by mixing nanoscale alumina particles with polytetrafluoroethylene (PTFE), which is known commercially as Teflon. Schadler and her research group introduced different fluorine-coated nanoparticles into conventional PTFE. The small amount of additive caused the wear rate of the PTFE to drop by four orders of magnitude, without affecting the PTFE's coefficient of friction. The end result is a stronger, more durable PTFE that is almost as nonstick and slippery as untreated PTFE.........

Posted by: Kevin      Read more         Source


July 26, 2009, 12:38 AM CT

Hubble captures rare Jupiter collision

Hubble captures rare Jupiter collision
The checkout and calibration of the NASA/ESA Hubble Space Telescope has been interrupted to aim the recently refurbished observatory at a new expanding spot on the giant planet Jupiter. The spot, caused by the impact of a comet or an asteroid, is changing from day to day in the planet's cloud tops.

For the past several days the world's largest telescopes have been trained on Jupiter. Not to miss the potentially new science in the unfolding drama 580 million kilometres away, Matt Mountain, director of the Space Telescope Science Institute in Baltimore, Maryland, allocated discretionary time to a team of astronomers led by Heidi Hammel of the Space Science Institute in Boulder, Colorado.

The Hubble picture, taken on 23 July, is the sharpest visible-light picture taken of the feature and is Hubble's first science observation following its repair and upgrade in May. Observations were taken with Hubble's new camera, the Wide Field Camera 3 (WFC3).

"This is just one example of what Hubble's new, state-of-the-art camera can do, thanks to the hard work of the astronauts and the entire Hubble team", said Ed Weiler, associate administrator of NASA's Science Mission Directorate. "Fortunately, the best is yet to come!".

"Hubble's truly exquisite imaging capability has revealed an astonishing wealth of detail in the 2009 impact site", said Hammel. "By combining these images with our ground-based data at other wavelengths, our Hubble data will allow a comprehensive understanding of exactly what is happening to the impact debris. My sincerest congratulations and thanks to the team who created Wide Field Camera 3 and to the astronauts who installed it!".........

Posted by: Brooke      Read more         Source


June 21, 2009, 9:25 PM CT

A glimpse of things to come

A glimpse of things to come
Herschel opened its 'eyes' on 14 June and the Photoconductor Array Camera and Spectrometer obtained images of M51, 'the whirlpool galaxy' for a first test observation. Researchers obtained images in three colours which clearly demonstrate the superiority of Herschel, the largest infrared space telescope ever flown.

This image shows the famous 'whirlpool galaxy', first observed by Charles Messier in 1773, who provided the designation Messier 51 (M51). This spiral galaxy lies relatively nearby, about 35 million light-years away, in the constellation Canes Venatici. M51 was the first galaxy discovered to harbour a spiral structure.

The image is a composite of three observations taken at 70, 100 and 160 microns, taken by Herschel's Photoconductor Array Camera and Spectrometer (PACS) on 14 and 15 June, immediately after the satellite's cryocover was opened on 14 June.

Herschel, launched only a month ago, is still being commissioned and the first images from its instruments were planned to arrive only in a few weeks. But engineers and researchers were challenged to try to plan and execute daring test observations as part of a 'sneak preview' immediately after the cryocover was opened. The objective was to produce a very early image that gives a glimpse of things to come.........

Posted by: Brooke      Read more         Source


April 27, 2009, 5:13 AM CT

Did dinosaurs die from an asteroid hit?

Did dinosaurs die from an asteroid hit?
The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a paper to be reported in the Journal of the Geological Society on April 27, 2009.

The crater, discovered in 1978 in northern Yucutan and measuring about 180 kilometers (112 miles) in diameter, records a massive extra-terrestrial impact.

When spherules from the impact were found just below the Cretaceous-Tertiary (K-T) boundary, it was quickly identified as the "smoking gun" responsible for the mass extinction event that took place 65 million years ago.

It was this event which saw the demise of dinosaurs, along with countless other plant and animal species.

However, many researchers have since disagreed with this interpretation.

The newest research, led by Gerta Keller of Princeton University in New Jersey, and Thierry Adatte of the University of Lausanne, Switzerland, uses evidence from Mexico to suggest that the Chicxulub impact predates the K-T boundary by as much as 300,000 years.

"Keller and his colleagues continue to amass detailed stratigraphic information supporting new thinking about the Chicxulub impact, and the mass extinction at the end of the Cretaceous," says H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research. "The two may not be linked after all".........

Posted by: William      Read more         Source


March 31, 2009, 2:52 PM CT

Ozone depletion from rocket launching

Ozone depletion from rocket launching
A Delta rocket launches from NASA's Kennedy Space Center carrying Mars Phoenix lander in 2007.

Credit: NASA

The global market for rocket launches may require more stringent regulation in order to prevent significant damage to Earth's stratospheric ozone layer in the decades to come, as per a newly released study by scientists in California and Colorado.

Future ozone losses from unregulated rocket launches will eventually exceed ozone losses due to chlorofluorocarbons, or CFCs, which stimulated the 1987 Montreal Protocol banning ozone-depleting chemicals, said Martin Ross, chief study author from The Aerospace Corporation in Los Angeles. The study, which includes the University of Colorado at Boulder and Embry-Riddle Aeronautical University, provides a market analysis for estimating future ozone layer depletion based on the expected growth of the space industry and known impacts of rocket launches.

"As the rocket launch market grows, so will ozone-destroying rocket emissions," said Professor Darin Toohey of CU-Boulder's atmospheric and oceanic sciences department. "If left unregulated, rocket launches by the year 2050 could result in more ozone destruction than was ever realized by CFCs".

A paper on the subject by Ross and Manfred Peinemann of The Aerospace Corporation, CU-Boulder's Toohey and Embry-Riddle Aeronautical University's Patrick Ross appeared online in March in the journal Astropolitics........

Posted by: Tyler      Read more         Source


January 8, 2009, 7:41 PM CT

Balloon Flight Test Over Antarctica

Balloon Flight Test Over Antarctica
A Long Duration Balloon (LDB) is inflated at the facility near McMurdo Station. This balloon carried the University of Maryland's Cosmic Ray Energetics and Mass (CREAM IV) payload, which studied the origins of cosmic rays.

Credit: Robyn Waserman, National Science Foundation
.
The National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA) have successfully launched and demonstrated a newly designed super pressure balloon prototype that will one day enable a new era of high-altitude scientific research. The super pressure balloon is expected to ultimately carry large scientific experiments to the brink of space for 100 days or more.

"This flight test of NASA's seven-million-cubic-foot super pressure balloon is a very important step forward in building a new capability for scientific ballooning based on sound engineering and operational development," said W. Vernon Jones, NASA's senior scientist for suborbital research at NASA Headquarters in Washington. "While the team has a ways to go in scaling up the pumpkin balloon to be able to lift a one-ton instrument to a float altitude of 110,000 feet, the team has demonstrated they are on the right path".

The super pressure balloon was highlighted in the National Research Council's decadal survey, "Astronomy and Astrophysics in the New Millennium," and will play an important role in providing inexpensive access to the near-space environment for science and technology.

The test flight was launched Dec. 28, 2008, from McMurdo Station, NSF's logistics hub in Antarctica. NASA and NSF conduct an annual scientific balloon campaign during the Antarctic summer. NSF manages the U.S. Antarctic Program and provides logistic support for all U.S. scientific operations in Antarctica.........

Posted by: Brooke      Read more         Source

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