Science & TechnologyS


Telescope

Wild, Hidden Cousin Of SN 1987A: Powerful Supernova Caught By Web Of Telescopes


Science Daily
Thu, 25 Sep 2008 13:17 UTC
The supernova, called SN 1996cr, was first singled out in 2001 by Franz Bauer. Bauer noticed a bright, variable source in the Circinus spiral galaxy, using NASA's Chandra X-ray Observatory. Although the source displayed some exceptional properties Bauer and his Penn State colleagues could not identify its nature confidently at the time.

Circinus galaxy
©X-ray (NASA/CXC/Columbia/F.Bauer et al); Visible light (NASA/STScI/UMD/A.Wilson et al.)
This composite image shows the central regions of the nearby Circinus galaxy, located about 12 million light years away. Data from NASA's Chandra X-ray Observatory is shown in blue and data from the NASA/ESA Hubble Space telescope is shown in yellow ("I-band"), red (hydrogen emission), cyan ("V-band") and light blue (oxygen emission). The blue source near the lower right hand corner of the image is the supernova SN 1996cr, that has finally been identified over a decade after it exploded. The supernova was first singled out in 2001 as a bright, variable object in a Chandra image, but it was not confirmed as a supernova until years later, when clues from a spectrum obtained with ESO's Very Large Telescope led the team to start the real detective work of searching through data from 18 different telescopes, both ground- and space-based, nearly all of which was in the archives. SN 1996cr is one of the nearest supernovae in the last 25 years.

It was not until years later that Bauer and his team were able to confirm that this object was a supernova. Clues from a spectrum obtained by ESO's Very Large Telescope led the team to start the real detective work of searching through data from 18 different telescopes, both ground- and space-based, nearly all of which existed. Because this object was found in an interesting nearby galaxy, the public archives of these telescopes contained abundant observations.
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Meteor

Artificial Meteorite Shows Martian Impactors Could Carry Traces Of Life


Science Daily
Thu, 25 Sep 2008 13:10 UTC
An artificial meteorite designed by the European Space Agency has shown that traces of life in a martian meteorite could survive the violent heat and shock of entry into the Earth's atmosphere. The experiment's results also suggest that meteorite hunters should widen their search to include white rocks if we are to find traces of life in martian meteorites.

Foton-M3 capsule
©Europlanet
The Foton-M3 capsule immediately after landing. The STONE-6 rock samples were fixed in the circular positions at the left side of the capsule.

The STONE-6 experiment tested whether sedimentary rock samples could withstand the extreme conditions during a descent though the Earth's atmosphere where temperatures reached at least 1700 degrees Celsius. After landing, the samples were transported in protective holders to a laboratory clean-room at ESTEC and examined to see if any traces of life remained. The results will be presented by Dr Frances Westall at the European Planetary Science Congress on 25th September.

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Telescope

Missing Link Of Neutron Stars? Bizarre Hibernating Stellar Magnet Discovered


Science Daily
Thu, 25 Sep 2008 13:00 UTC
Astronomers have discovered a most bizarre celestial object that emitted 40 visible-light flashes before disappearing again. It is most likely to be a missing link in the family of neutron stars, the first case of an object with an amazingly powerful magnetic field that showed some brief, strong visible-light activity.

magnetar
©ESO/L.Calçada
Astronomers have discovered a possible magnetar that emitted 40 visible-light flashes before disappearing again. Magnetars are young neutron stars with an ultra-strong magnetic field a billion billion times stronger than that of the Earth. The twisting of magnetic field lines in magnetars give rise to 'starquakes', which will eventually lead to an intense soft gamma-ray burst. In the case of the SWIFT source, the optical flares that reached the Earth were probably due to ions ripped out from the surface of the magnetar and gyrating around the field lines.

This weird object initially misled its discoverers as it showed up as a gamma-ray burst, suggesting the death of a star in the distant Universe. But soon afterwards, it exhibited some unique behaviour that indicates its origin is much closer to us. After the initial gamma-ray pulse, there was a three-day period of activity during which 40 visible-light flares were observed, followed by a brief near-infrared flaring episode 11 days later, which was recorded by ESO's Very Large Telescope. Then the source became dormant again.

"We are dealing with an object that has been hibernating for decades before entering a brief period of activity", explains Alberto J. Castro-Tirado, lead author of a new paper in the journal Nature.
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Telescope

Deep Interior Of Neptune, Uranus And Earth May Contain Some Solid Ice


Science Daily
Wed, 24 Sep 2008 12:51 UTC
The deep interior of Neptune, Uranus and Earth may contain some solid ice.

Through first-principle molecular dynamics simulations, Lawrence Livermore National Laboratory scientists, together with University of California, Davis collaborators, used a two-phase approach to determine the melting temperature of ice VII (a high-pressure phase of ice) in pressures ranging from 100,000 to 500,000 atmospheres.

Image
©Visualization by Eric Schwegler/LLNL
A snapshot from a first-principle molecular dynamics simulation of ice-VII (on the right) in contact with liquid water (on the left). As the simulation progresses the position of the solid-liquid interface can be monitored and used to accurately determine the location of the melting temperature of water under high pressure conditions.

For pressures between 100,000 and 400,000 atmospheres, the team, led by Eric Schwegler, found that ice melts as a molecular solid (similar to how ice melts in a cold drink). But in pressures above 450,000 atmospheres, there is a sharp increase in the slope of the melting curve due to molecular disassociation and proton diffusion in the solid, prior to melting, which is typically referred to as a superionic solid phase.

"The sharp increase in the melting curves slope opens up the possibility that water exists as a solid in the deep interior of planets such as Neptune, Uranus and Earth," Schwegler said.
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Telescope

Finding Fireflies Next To A Lighthouse: New Optics Technology To Study Alien Worlds


Science Daily
Wed, 24 Sep 2008 12:46 UTC
NASA Goddard scientist Rick Lyon has been working on potential missions and technologies to find planets around other stars (called exoplanets or extrasolar planets) since the late 1980s. Only recently has he begun to believe that NASA may actually fly a planet-finding mission in his lifetime. "This is the closest it's come to being real," he said.

New Worlds Observatory
©NASA and Northrop Grumman
Artist's concept of the New Worlds Observatory. The dark, flower-shaped object in the center is the star shade.

Lyon and other scientists and engineers at NASA's Goddard Space Flight Center in Greenbelt, Md., have joined teams studying optics technologies for three possible exoplanet missions: the Extrasolar Planetary Imaging Coronagraph (EPIC), the New Worlds Observer (NWO), and the eXtrasolar Planet Characterization (XPC) mission.

The possibility of a mission devoted to planet finding is tantalizing, especially to those interested in ratcheting up a science that began 13 years ago when astronomers found and confirmed the existence of the first planet outside the solar system. Since then, scientists have confirmed nearly 300, most of which are gas giants like Jupiter. However, most of these detections have been indirect, because the planets are too faint to be seen directly. Instead, their presence is revealed by measuring how much the unseen world's gravity pulls on its parent star.
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Telescope

Two Planets Suffer Violent Collision


Science Daily
Wed, 24 Sep 2008 12:07 UTC
Two terrestrial planets orbiting a mature sun-like star some 300 light-years from Earth recently suffered a violent collision, astronomers at UCLA, Tennessee State University and the California Institute of Technology will report in a December issue of the Astrophysical Journal.

Image
©Lynette R. Cook
An artist's rendering depicts planets colliding in a sun-like binary system about 300 light-years from Earth, in the constellation Aries.

"It's as if Earth and Venus collided with each other," said Benjamin Zuckerman, UCLA professor of physics and astronomy and a co-author on the paper. "Astronomers have never seen anything like this before. Apparently, major catastrophic collisions can take place in a fully mature planetary system."

"If any life was present on either planet, the massive collision would have wiped out everything in a matter of minutes - the ultimate extinction event," said co-author Gregory Henry, an astronomer at Tennessee State University (TSU). "A massive disk of infrared-emitting dust circling the star provides silent testimony to this sad fate."
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Display

Where monkey films meet Sarah Palin

Colin Barras
New Scientist
Mon, 22 Sep 2008 21:52 UTC
Material online can seem ephemeral. Here's a welcome example of the opposite. Earlier this year a site called Deletionpedia launched with the sole aim of preserving all the pages deleted from Wikipedia.

There are already some 64,000 pages saved for posterity, with more accumulating every day. Some pages seem to have been deleted - and created - for political reasons.
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Info

NASA ramps up weather research with supercomputer cluster

Jon Brodkin
Network World
Tue, 23 Sep 2008 20:55 UTC
NASA's Center for Computational Sciences is nearly tripling the performance of a supercomputer it uses to simulate Earth's climate and weather, and our planet's relationship with the Sun.

NASA is deploying a 67-teraflop machine that takes advantage of IBM's iDataPlex servers, new rack-mount products originally developed to serve heavily trafficked social networking sites. The servers use an innovative design that saves on power and cooling costs by placing the servers sideways and using a liquid-cooled rear-door heat exchanger.
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Clock

Ulysses Reveals Global Solar Wind Plasma Output At 50-Year Low

Dwayne Brown, DC Agle
NASA
Tue, 23 Sep 2008 16:01 UTC
Washington -- Data from the Ulysses spacecraft, a joint NASA-European Space Agency mission, show the sun has reduced its output of solar wind to the lowest levels since accurate readings became available. The sun's current state could reduce the natural shielding that envelops our solar system.

"The sun's million mile-per-hour solar wind inflates a protective bubble, or heliosphere, around the solar system. It influences how things work here on Earth and even out at the boundary of our solar system where it meets the galaxy," said Dave McComas, Ulysses' solar wind instrument principal investigator and senior executive director at the Southwest Research Institute in San Antonio. "Ulysses data indicate the solar wind's global pressure is the lowest we have seen since the beginning of the space age."

Image
©NASA
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Telescope

Saturn's Rings May Be More Massive, Older, Than Previously Thought


Science Daily
Tue, 23 Sep 2008 13:58 UTC
Saturn's rings may be more massive than previously thought, and potentially much older, according to calculations that simulate colliding particles in Saturn's rings and their erosion by meteorites.

Image
©Voyager 2, NASA
Saturn's rings may be more massive than previously thought, and potentially much older.

These results support the possibility that Saturn's rings formed billions of years ago, perhaps at the time when giant impacts excavated the great basins on the Moon. The findings also suggest that giant exoplanets may also commonly have rings.
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