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February 22, 2006, 11:07 PM CT

New Infrared Sky Surveyor

New Infrared Sky Surveyor Image Credits: ESA and JAXA
A high-capability new infrared satellite, ASTRO-F, was successfully launched last night by the Japan Aerospace Exploration Agency (JAXA). In a collaborative effort involving ESA and researchers across Europe, the spacecraft is now being prepared to start its mapping of the cosmos.

Orbiting the Earth, ASTRO-F (to be renamed Akari (light) now that it is in orbit) will make an unprecedented study of the sky in infrared light, to reveal the distant phenomena hidden from our eyes that tell the story of the formation and evolution processes taking place in the universe.

Prof. David Southwood, ESA's Director of Science, said: "The successful launch of ASTRO-F (Akari) is a big step. A decade ago, our Infrared Space Observatory (ISO) opened up this field of astronomy, and the Japanese took part then. It is wonderful to be cooperating again with Japan in this discipline."

"Our involvement with the Japanese in this programme responds to our long-term commitment in infrared astronomy, whose potential for discovery is huge. We are now off and rolling with ASTRO-F/Akari, but we are also working extremely hard towards the launch of the next-generation infrared telescope, ESA's Herschel spacecraft, which will go up in the next two years," he continued.

"This will not yet be the end of the story. Infrared astronomy is also a fundamental part of the future vision for ESA's space research, as outlined in the 'Cosmic Vision 2015-2025' programme. The truth is, subjects such as the formation of stars and exoplanets, or the evolution of the early universe, are themes at the very core of our programme." .........

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February 20, 2006, 10:50 PM CT

Shadow on the surface of Mars

Shadow on the surface of Mars
These images, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show the fast-moving shadow of the moon Phobos as it moved across the Martian surface.

The HRSC obtained these unique images during orbit 2345 on 10 November 2005. These observations would not have been possible without the close co-operation between the camera team at the Institute of Planetary Research at DLR and the ESA teams, in particular the mission engineers at ESA's European Space Operations Centre (ESOC) in Darmstadt, Gera number of.

They confirm the model of the moon's orbit around Mars, as it was determined earlier in 2004 also on the basis of HRSC images. They also show that with accurate planning even moving objects can be captured exactly at their predicted position.

The basis for such observations is the accurate knowledge of the spacecraft position in its orbit as well as of the targeted location on Mars to within a few hundred metres.

Phobos is the larger of the two Martian moons, 27 kilometres by 22 kilometres in size, and travels around Mars in an almost circular orbit at an altitude of about 6000 kilometres. Phobos takes slightly more than 7.5 hours to complete a full revolution around the planet.

When it is between the Sun and Mars, Phobos casts a small and diffuse shadow onto the Martian surface. To an observer on Mars, this would appear as a very quick eclipse of the Sun. This is similar to an eclipse on Earth, when the Moon covers the solar disk but much slower.........

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February 20, 2006, 7:48 PM CT

A Spinning Black Hole And indentation In Spacetime

A Spinning Black Hole And indentation In Spacetime Artist impression of the black hole binary system GRO J1655-40 (Rob Hynes) Image courtesy of University of Michigan
A University of Michigan scientist is part of a team that discovered a black hole that has chiseled a stable dent in the fabric of space and time, like a dimple in one's favorite spot on a sofa.

The finding may help researchers measure a black hole's mass and how it spins, two long-sought measurements, by virtue of the extent of this indentation. Using NASA's Rossi X-ray Timing Explorer, the team of researchers saw identical patterns in the X-ray light emitted near the black hole over nine years, as captured in archived data from 1996 and in a new, unprecedented 550-hour observation from 2005.

Black hole regions are notoriously chaotic, generating light at a range of frequencies. Similarities seen nine years apart imply something fundamental is producing a pair of observed frequencies, namely the warping of space and time predicted by Einstein but rarely seen in such detail.

Jeroen Homan of MIT's Kavli Institute and his team, which included Jon Miller of U-M, Rudy Wijnands of Amsterdam University and Walter Lewin of MIT, presented the result at the American Astronomical Society meeting in Washington this week.

"The fact that we found the exact same frequency of X-ray oscillations nine years later is likely no coincidence," Homan said. "The black hole is still singing the same tune. The oscillations are created by a groove hammered into spacetime by the black hole. This phenomenon has been suspected for a while, but now we have good evidence to support it."........

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February 19, 2006, 10:31 AM CT
Tiny Crystals in Violent Galaxies
An artist's illustration showing the greenish tiny crystals sprinkled throughout the core of a pair of colliding galaxies. Image credit: NASA Click to enlarge
Wed, 15 Feb 2006 - Spitzer has uncovered an unusual pair of colliding galaxies whose hearts are surrounded by tiny crystals that resemble crushed glass. These crystals look like sand, and were probably shed from massive stars before and while they exploded as supernovae. Although these crystals have been seen in the Milky Way, this is the first time they've been found outside our galaxy. They won't last long, however. Scientists think the crystals will get heated up again and again by multiple supernova blasts and eventually melt back into a shapeless form.


Read more....


February 15, 2006, 11:09 PM CT

Galaxies That Contain Massive Young Stars

Galaxies That Contain Massive Young Stars This image illustrates how two galaxies could be torn apart by their mutual attraction, causing whole strains of stars to be catapulted out to form something like antennae. The galaxies' nuclei would dance around each other and eventually merge to form a single nucleus.
The discovery makes the fiery environment within a typical spiral or starburst galaxy look almost pastoral. Cornell scientists using the Spitzer Space Telescope say distant galaxies contain an inferno of very young, massive and violently evolving stars, packed together in tiny but extremely powerful cosmic globs.

The key to the discovery, paradoxically, is in the presence of delicate, glittery crystalline silicates called Forsterite. These are glassy particles that exist in the debris disks of young stars and in the stellar wind of very old stars, but which have never before been observed in the mass of gas and dust known as the interstellar medium, or ISM, in the Milky Way or in any other galaxy.

The research, led by Cornell astronomer and Spitzer Fellow Henrik Spoon, will appear in the Feb. 20 issue of the Astrophysical Journal.

Using Spitzer's infrared spectrograph (IRS), an instrument developed by a team led by Cornell professor of astronomy James Houck and built at Cornell, Spoon and his colleagues observed dozens of distant galaxies known as ultra-luminous infrared galaxies (ULIRGs). First discovered in large numbers in 1982, most ULIRGs are thought to form as two or more spiral galaxies collide (as our galaxy will, in a few billion years, with the nearby Andromeda galaxy), and their leftover hydrogen gas fuels the fierce, rapid formation of massive stars.........

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February 13, 2006, 10:59 PM CT

Perspective View Of Phlegethon Catena

Perspective View Of Phlegethon Catena
This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, show pits and tectonic 'grabens' in the Phlegethon Catena region of Mars.

The HRSC obtained this images during orbit 1217 with a ground resolution of approximately 11.9 metres per pixel. The scenes show the region of Phlegethon Catena, centred at approximately 33.9 degree South and 253.1 degree East.

Located south-east of the Alba Patera volcano, Phlegethon Catena is a region exhibiting a high density of tectonic grabens, which are blocks of terrain that have dropped relative to their surroundings as a result of a geological extension of the crust.

It is unclear what process is responsible for the chain of depressions.

One possibility is the collapse of the surface due to the removal of subsurface materials, while other suggestions include that tension cracks may have formed in the subsurface and caused subsequent collapse.

The colour scenes have been derived from the three HRSC-colour channels and the nadir channel. The perspective views have been calculated from the digital terrain model derived from the stereo channels.

The 3D anaglyph image was calculated from the nadir and one stereo channel. Image resolution has been decreased for use on the internet.........

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February 12, 2006, 8:07 PM CT

RAVE to reveal Galaxy's history

RAVE to reveal Galaxy's history The RAVE survey's telescope
Clues to how galaxies formed in the early Universe lie right under our nose - in our own Galaxy. The Galaxy formed by the accretion of infalling satellite galaxies, a number of astronomers think. Theoretical models of the formation of galaxies predict such a scenario.

But not all astronomers are convinced yet and the topic is still controversial. Now scientists from eleven countries have launched an ambitious project to reconstruct our Galaxy's history by gathering key components of motion and chemical compositions for its apparently brightest 50 million stars. RAVE (RAdial Velocity Experiment) is an all-sky stellar spectroscopy survey just started on the 1.2-m UK Schmidt telescope in eastern Australia. Projects such as Hipparcos and Tycho have accurately measured the positions and proper motions - movement across the sky - of more than 2.5 million stars. But to get a complete picture of stellar motions, and thus to enable astronomers to reconstruct the structure and formation history of our Galaxy, they also need radial velocities - the movement of stars towards or away from the observer. And before RAVE began only about 20,000 stellar radial velocities were in the archives.

RAVE will be able to achieve velocities accurate to within 2 kms-1 - about 1% of the speed at which stars typically move in the Galaxy. "With this accuracy and this number of radial velocities we will be able to identify dozens, perhaps hundreds, of streams of stars in the solar vicinity.........

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February 9, 2006, 10:53 PM CT

Mysterious 'floppy' Space Molecule Explained

Mysterious 'floppy' Space Molecule  Explained A research team at JILA has developed a new method for making and analyzing an unusual floppy molecule.
A laboratory method developed for making and analyzing cold, concentrated samples of a mysterious "floppy" molecule believed to be abundant only in outer space has revealed new data that help explain the molecule's properties.

The advance, described in the Jan. 6 issue of Science,* is a step toward overcoming a decades-old challenge in chemistry-explaining reactions that occur within very cold clouds among the stars, and perhaps for developing new chemical processes. The paper combines experiments performed by David Nesbitt and his colleagues at JILA, a joint institute of the Commerce Department's National Institute of Standards and Technology (NIST) and University of Colorado at Boulder, with theoretical predictions made with Joel Bowman at Emory University in Atlanta, Ga., and Anne McCoy at The Ohio State University in Columbus, Ohio.

Most molecules have a rigid three-dimensional (3D) structure. The subject of the new study is "protonated" methane, which contains one carbon atom and five hydrogen atoms, one of which is ionized, leaving nothing but a proton (a particle with a positive charge). The five protons from the hydrogen atoms scramble for four bonds around the molecule as if playing a continuous game of musical chairs. In the process, the molecule classically vibrates and rotates in a bizarre manner, morphing between several 3D structures with nearly identical energy levels. (Animation available at http://www.nist.gov/public_affairs/images/floppy_animation.htm.) Chemists have spent decades trying to explain why and how this occurs, a challenge that has seemed insurmountable until recently.........

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February 8, 2006, 11:14 PM CT

Rough and Tumble Hyperion

Rough and Tumble Hyperion
The tumbling and irregularly shaped moon Hyperion hangs before Cassini in this image taken during a distant encounter in Dec. 2005. This still image is part of a movie sequence of 40 images taken over about two hours as Cassini sped past the icy moon (see the related movie).

Hyperion (280 kilometers, or 174 miles across) is covered with closely packed and deeply etched pits. The warming action of the Sun on water ice lying beneath a darkened layer of surface material apparently has deepened and exaggerated the depressions already created by impacts.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 23, 2005 at a distance of 228,000 kilometers (142,000 miles) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 77 degrees. Resolution in the original image was about 1.4 kilometers (0.9 mile) per pixel. The image was magnified by a factor of two and contrast-enhanced to aid visibility.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.........

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February 7, 2006, 10:43 PM CT

Martian Snow Source Of Tropical Glaciers

Martian Snow Source Of Tropical Glaciers
Snow is the source of glacial deposits found at the base of the majestic volcanoes and mountains dotting the mid-latitude and tropical regions of Mars. Based on an innovative blend of geological observations and climate modeling created by a team of American and French scientists, the finding appears in Science.

Discovery of the source of the tropical glaciers ends a 30-year Martian mystery. In 1976, cameras aboard NASA's Viking Mission to Mars captured unprecedented views of the canyons and craters of the Red Planet - including polar ice caps. Recent spacecraft data reveal curious rock-strewn deposits found at the foot of volcanoes and mountains close to the equator.

In the last two years, Brown University planetary geologist James Head and other Mars experts have offered up mounting evidence that these ice-rich landforms - which appear to ooze out of valleys in the Eastern Hellas region or puddle on the western flanks of the three giant volcanoes known as the Tharsis Montes - are the remnants of geologically recent glaciers.

But how could ice form so far from the planet's poles? Long-ago landslides? Upwelling from an underground reservoir?.

"What we found," Head said, "was that the glaciers were formed from snow brought from the polar regions".........

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