October 4, 2007, 4:55 AM CT

Black holes, galaxies young and old visible in massive mapping

Color images documenting the past 10 billion years of galactic evolution were distributed online this week as part of the first public release of data from a massive project to map a distant region of the universe that combines the efforts of nearly 100 scientists from around the world, including the University of Pittsburgh.

Scientists in the All-wavelength Extended Groth Strip International Survey, or AEGIS, observed the same small region of sky using all available wavelengths of the electromagnetic spectrum--from X-rays to ultraviolet, visible, infrared, and radio waves. The survey focused on the Extended Groth Strip, an area the width of four full moons near the "handle" of the Big Dipper constellation. Four color images from four different satellite telescopes, as well as numerous data catalogs tabulating the properties of and distances to tens of thousands of galaxies, are now available on both the AEGIS Web site and Google Sky, a downloadable program that allows home computer users to explore these distant galaxies up close and in sharp detail.

Pitt physics and astronomy professor Jeffrey Newman is a key member of the AEGIS project's core team, the Deep Extragalactic Evolutionary Probe, or DEEP2 team. That team measured optical spectra-detailed breakdowns of the amount of light of a given color we see--for 50,000 galaxies, including 14,000 galaxies in the Extended Groth Strip. These spectra tie together all of the AEGIS datasets by allowing the team to determine each galaxy's distance from Earth. Once the distance is known, astronomers know how far back in time light left a galaxy and, thus, its age. The most distant galaxies in the survey-up to 9 billion light years away-appear as they were only a few billion years after the Big Bang......... Posted by: Sean      Read more         Source

October 2, 2007, 10:21 PM CT

Extreme star cluster in new Hubble images

The gigantic nebula NGC 3603 hosts one of the most prominent, massive, young clusters in the Milky Way. Hubble has been observing this prime location for star formation studies.

NGC 3603 is located in the Carina spiral arm of the Milky Way, about 20 000 light-years from the Solar System.

Images from the NASA/ESA Hubble Space Telescope show a young star cluster surrounded by a vast region of dust and gas. Most of the bright stars in the image are hot, blue stars. They produce ultraviolet radiation and violent winds that have formed an enormous cavity in the gas and dust surrounding the cluster.

The image shows a number of stars with differing masses but similar ages inside the young cluster. Stars of different masses evolve at a different pace, so this makes it possible to study several types of stars at varying stages in their lives, in detail. Astronomers can compare clusters of different ages with one another and determine which properties (such as temperature and brightness) change as the stars get older.

Dr Jesús Maíz Apellániz from Instituto de Astrofísica de Andalucía, Spain, is leading the Hubble investigation. As per him, the cluster appears to gather the most massive stars at its core. His team has discovered that the distribution of different types of stars at the centre of this dense cluster is similar to that of other young clusters in the Milky Way......... Posted by: Sean      Read more         Source

October 2, 2007, 10:11 PM CT

Titan's icy climate mimics Earth's tropics

If space travelers ever visit Saturn's largest moon, they will find a tropical world where temperatures plunge to minus 274 degrees Fahrenheit, methane rains from the sky and dunes of ice or tar cover the planet's most arid regions. These conditions reflect a cold mirror image of Earth's tropical climate, as per researchers at the University of Chicago.

"You have all these things that are analogous to Earth. At the same time, it's foreign and unfamiliar," said Ray Pierrehumbert, the Louis Block Professor in Geophysical Sciences at Chicago.

Titan, one of Saturn's 60 moons, is the only moon in the solar system large enough to support an atmosphere. Pierrehumbert and Jonathan Mitchell, who recently completed his Ph.D. in Astronomy & Astrophysics at Chicago, have been comparing observations of Titan collected by the Cassini space probe and the Hubble Space Telescope with their own computer simulations of the moon's atmosphere.

Their study of the dynamics behind Titan's methane clouds have appeared in the Proceedings of the National Academy of Sciences. Their continuing research on Titan's climate focuses on the moon's deserts.

"One of the things that attracts me about Titan is that it has a lot of the same circulation features as Earth, but done with completely different substances that work at different temperatures," Pierrehumbert said. On Earth, for example, water forms liquid and is relatively active as a vapor in the atmosphere. But on Titan, water is a rock......... Posted by: Sean      Read more         Source

October 1, 2007, 10:19 PM CT

'Embryonic Planets' Forming in Nearby Stellar Systems

Astronomers at the University of Rochester are pointing to three nearby stars they say may hold "embryonic planets"-a missing link in planet-formation theories.

As researchers try to piece together how our own planet came to be, they look to the forming planets of other star systems for clues. But astronomers have been unable to find evidence for one of the key stages of planet development, a period early in the planet's formation when it is only as large as tiny Pluto.

In an attempt to reveal this hidden phase of a planet's life, Alice Quillen, associate professor of astronomy at the University of Rochester, employed new Hubble Space Telescope imagery to measure the thickness of the dust disks that surround forming stars, and to calculate the size of the planets growing within.

The results help paint a picture of a planet's earliest years, and tell us how our own small planet probably began its life, says Quillen.

Researchers have inferred the presence of nearly 250 planets in the last decade, but Quillen's method focuses on a unique aspect: the proto-planetary disk's thickness.

Quillen explains that a disk of gritty dust commonly surrounds forming stars, and provides the raw material for planet building. The cloud of dust thins as the system ages, but if enough dust has clumped together, the "embryonic planet," as Quillen calls it, will knock the dust and grit into ever-more eccentric orbits. Over time, this will cause an otherwise razor-thin disk to appear puffed up......... Posted by: Sean      Read more         Source

October 1, 2007, 9:08 PM CT

Chance encounter with comet nets surprising results

Comets are made of the most primitive stuff in the solar system. As hunks of rock and ice that never coalesced into more planets, they give scientists clues to the evolution of solar systems.

So a chance encounter between spacecraft Ulysses and Comet McNaught's ion tail has researchers in the University of Michigan's College of Engineering marveling at a stroke of luck and some surprising data.

The NASA/European Space Agency spacecraft is on a mission to study the sun's polar regions, and it carries an instrument run by U-M professors. In February, it flew through McNaught's ion tail 160 million miles from the comet's core.

Instrument readings showed there was "complex chemistry" at play, said U-M space science professor George Gloeckler, second author of a paper on the findings published Oct. 1 in Astrophysical Journal.

Gloeckler is the principal investigator on the Solar Wind Ion Composition Spectrometer (SWICS) aboard Ulysses, which measured the composition and speed of the comet tail and solar wind. The solar wind consists of high-speed streams of plasma that emanate from the sun's outer atmosphere. Not only did SWICS detect unexpected ions in the comet tail, it observed that the tail had a major impact on the surrounding solar wind......... Posted by: Sean      Read more         Source

September 24, 2007, 10:11 PM CT

Cornucopia of Earth-sized Planets

In the Star Wars movies fictional planets are covered with forests, oceans, deserts, and volcanoes. But new models from a team of MIT, NASA, and Carnegie researchers begin to describe an even wider range of Earth-size planets that astronomers might actually be able to find in the near future.

Sara Seager, Massachusetts Institute of Technology, Cambridge, Mass.; Marc Kuchner, NASA Goddard Space Flight Center, Greenbelt, Md.; Catherine Hier-Majumder, Carnegie Institution of Washington, (deceased); and Burkhard Militzer, Carnegie, have created models for 14 different types of solid planets that might exist in our galaxy. The 14 types have various compositions, and the team calculated how large each planet would be for a given mass. Some are pure water ice, carbon, iron, silicate, carbon monoxide, and silicon carbide; others are mixtures of these various compounds.

"We're thinking seriously about the different kinds of roughly Earth-size planets that might be out there, like George Lucas, but for real," says Kuchner.

The team took a different approach from prior studies. Rather than assume that planets around other stars are scaled-up or scaled-down versions of the planets in our solar system, they considered all types of planets that might be possible, given what astronomers know about the composition of protoplanetary disks around young stars......... Posted by: Sean      Read more         Source

September 23, 2007, 11:07 AM CT

Reading the planetary tea leaves

An international team of astronomers is one step closer to answering the question, "Will the world end with a bang or a whimper?".

Using an array of telescopes around the globe, a team of 23 scientists led by Italian astronomer Dr. Roberto Silvotti of the Observatorio Astronomico di Capodimonte in Naples has spent seven years investigating the pulses of the star V391 Pegasi. This international collaboration has resulted in the discovery of a new planet Peg V392b the oldest planet known so far in the universe.

Prof. Elia Leibowitz, of Tel Aviv University's School of Physics and Astronomy was a member of the team. To date, astronomers around the world have discovered more than 200 planets outside our solar system, but Prof. Leibowitz says his new discovery can shed light on the state of our planets future.

Prof. Leibowitz made his observations with a team at Tel Aviv Universitys Wise Observatory home to one of only a few telescopes in use today in the Middle East.

The Peg V391 star unlike our sun, has already passed the "red giant" stage of its life. It is presently shrinking, on its way to becoming a white dwarf and dying, he explains. Because a planet linked to Peg V391 has now been found, for the first time astronomers will be able to study the effect a dying sun has on its planet. This will help draw conclusions about what will happen to planet Earth when our sun starts dying in about 5 billion years......... Posted by: Sean      Read more         Source

September 21, 2007, 6:46 AM CT

Orphan stars found in long galaxy tail

Astronomers have found evidence that stars have been forming in a long tail of gas that extends well outside its parent galaxy. This discovery suggests that such "orphan" stars may be much more prevalent than previously thought.

The comet-like tail was observed in X-ray light with NASA's Chandra X-ray Observatory and in optical light with the Southern Astrophysical Research (SOAR) telescope in Chile. The feature extends for more than 200,000 light years and was created as gas was stripped from a galaxy called ESO 137-001 that is plunging toward the center of Abell 3627, a giant cluster of galaxies.

"This is one of the longest tails like this we have ever seen," said Ming Sun of Michigan State University, who led the study. "And, it turns out that this is a giant wake of creation, not of destruction."

The observations indicate that the gas in the tail has formed millions of stars. Because the large amounts of gas and dust needed to form stars are typically found only within galaxies, astronomers have previously thought it unlikely that large numbers of stars would form outside a galaxy.

"This isn't the first time that stars have been seen to form between galaxies," said team member Megan Donahue, also of MSU. "But the number of stars forming here is unprecedented"......... Posted by: Sean      Read more         Source

September 21, 2007, 6:38 AM CT

Carnegie Mellon Building Robot for Lunar Prospecting

Scientists in the Robotics Institute of Carnegie Mellon University's School of Computer Science are building a robotic prospector for NASA that can creep over rocky slopes and then anchor itself as a stable platform for drilling deep into extraterrestrial soils.

Called "Scarab," this four-wheeled robot will never leave the Earth. But it will demonstrate technologies that a lunar rover will need to find concentrations of hydrogen, possibly water and other volatile chemicals on the moon that could be mined to produce fuel, water and air that are essential for supporting lunar outposts.

Scarab is equipped with a Canadian-made drill for obtaining meter-long geological core samples and features a novel rocker-arm suspension that enables the robot to plant its belly on the ground for drilling operations.

"A lunar prospector will face a hostile environment in the perpetual darkness of craters at the moon's southern pole, where ground temperatures are minus 385 degrees and no energy source is at hand," said William "Red" Whittaker, the Fredkin Research Professor and principal investigator of the NASA-funded project. "It's a place where humans can't work effectively, but where Scarab will thrive, even while operating on the electrical power mandatory to illuminate a 100-watt light bulb"......... Posted by: Sean      Read more         Source

September 18, 2007, 5:36 AM CT

Lift-off for Foton microgravity mission

An unmanned Foton spacecraft, carrying a payload of more than 40 ESA experiments, was successfully launched earlier today. The Soyuz-U launcher lifted off from Baikonur Cosmodrome, Kazakhstan, at 13:00 CEST (11:00 GMT).

Nearly 9 minutes later, the Russian Foton-M3 spacecraft separated from the rocket's upper stage and was inserted into a 300 km orbit that will carry it around the Earth once every 90 minutes.

The Foton will spend 12 days in orbit, during which time the onboard experiments will be exposed to microgravity, and in some cases, to the harsh environment of open space, before re-entering the atmosphere and landing on the steppes near the Russian-border.

The 400 kg European payload includes experiments that will contribute to advances in a number of areas of research. The scientific experiments come from a wide range of scientific disciplines, including fluid physics, biology, protein crystal growth, meteoritics, radiation dosimetry and exobiology (life beyond Earth). The technology-related experiments may lead to more efficient oil extraction processes, better semiconductor alloys and more efficient thermal control systems.

"The Foton mission is part of ESA's programme for Life and Physical Sciences in spaceexplained Josef Winter, Head of ESA's Payload and Microgravity Platform Division......... Posted by: Sean      Read more         Source