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MESSENGER Spacecraft Reveals New Insights on Planet Mercury

March 22, 2012 Leave a comment

Thanks to the MESSENGER spacecraft, and a mission that took more than 10 years to complete, scientists now have a good picture of the solar system’s innermost planet.

On March 17, MESSENGER (MErcury Surface, Space Environment, GEochemistry, and Ranging) completed its one-year primary mission, orbiting Mercury, capturing nearly 100,000 images, and recording data that reveals new information about the planet’s core, topography, and the mysterious radar bright material in the permanently shadowed areas near the poles. The findings are presented in two papers published online in Science Express.

“Mercury is the last unexplored planet,” said UC Santa Barbara physics professor emeritus Stanton Peale, who devised the procedure used for detecting whether or not Mercury had a liquid core. The way Mercury was formed, he said, may show some constraints on the formation of the solar system.

For one thing, Mercury’s core is larger than expected –– almost 85 percent of the planetary radius. The Earth’s core, in contrast, is just over half of the planet’s radius. Additionally, Mercury appears to have a more complex core than Earth’s –– a solid iron sulfide layer that is now part of the mantle, which encases a liquid core, which may float on a solid inner core.

Full Story: http://www.ia.ucsb.edu/pa/display.aspx?pkey=2677

VISTA Produces Spectacular Panoramic View of the Distant Universe

March 22, 2012 Leave a comment

The most detailed infrared image ever taken of a region of space large enough to be representative of the distant Universe has been released by a team led by the University of Edinburgh. The image from the European Southern Observatory’s (ESO) VISTA telescope reveals more than 200,000 galaxies, including the most distant seen to date in the early Universe. These objects formed less than one billion years after the Big Bang. The new image comes from the first year of data taken as part of the five-year UltraVISTA survey. It was made by combining more than six thousand separate images – equivalent to an exposure time of 55 hours.

The image forms part of a huge collection of fully processed images from all the VISTA surveys that is now being made available by ESO to astronomers worldwide. It comes as a result of the VISTA telescope being trained on the same patch of sky repeatedly to slowly accumulate the very dim light from the most distant galaxies. On this colour composite of the UltraVISTA image, the large white objects with haloes are foreground stars in our own Milky Way Galaxy. A host of other galaxies can be seen, from relatively nearby galaxies which appear large enough to discern their structures, to the most distant galaxies which appear as red dots in this image.
Professor Jim Emerson, of Queen Mary, University of London, Principal Investigator for the construction of VISTA, commented: “These superbly detailed images of such a large area of the distant Universe are an exciting first return for the ten years the team spent getting VISTA from an idea to a successful reality.”

Full Story: http://www.stfc.ac.uk/News+and+Events/38774.aspx

NASA’s Dawn Sees New Surface Features on Giant Asteroid Vesta

March 22, 2012 Leave a comment

NASA’s Dawn spacecraft has revealed unexpected details on the surface of the giant asteroid Vesta. New images and data highlight the diversity of Vesta’s surface and reveal unusual geologic features, some of which were never previously seen on asteroids.

Vesta is one of the brightest objects in the solar system and the only asteroid in the so-called main belt between Mars and Jupiter visible to the naked eye from Earth. Dawn found that some areas on Vesta can be nearly twice as bright as others, revealing clues about the asteroid’s history.

“Our analysis finds this bright material originates from Vesta and has undergone little change since the formation of Vesta over 4 billion years ago,” said Jian-Yang Li, a Dawn participating scientist at the University of Maryland, College Park. “We’re eager to learn more about what minerals make up this material and how the present Vesta surface came to be.”

Full Story: http://www.nasa.gov/home/hqnews/2012/mar/HQ_12-091_Dawn_Vesta_Features.html

Surprising Discovery of a Rare “Emerald-Cut” Galaxy

March 22, 2012 Leave a comment

An international team of astronomers—from Australia, Germany, Switzerland, and Finland—has discovered a rare, rectangular-shaped galaxy (LEDA 074886) that has a striking resemblance to an emerald-cut diamond. While using the Subaru Prime Focus Camera (Suprime-Cam) to look for globular clusters of stars swarming around NGC 1407, a bright, giant galaxy in the Constellation Eridanus and 70 million light years from Earth, the researchers discovered an unusually shaped dwarf galaxy toward the edge of their image. Professor Alister Graham (Swinburne University of Technology, Australia), lead author of the paper describing the research, said, “It’s one of those things that just makes you smile because it shouldn’t exist, or rather, you don’t expect it to exist.” Its discovery allows astronomers to obtain useful information for modeling other galaxies.

Most galaxies in the universe around us exist in one of three forms: ellipsoidal, disk-like (usually in the shape of a flattened circular disk hosting a spiral pattern of stars), or irregular. Dwarf galaxies, probably the most common galaxies in the Universe, are small and have low intrinsic brightness (i.e., luminosity). One of the reasons that LEDA 074886 was hard to find is its dwarf-like status; it has 50 times less stars than our own Milky Way Galaxy, and its distance from Earth is equivalent to that spanned by 700 Milky Way galaxies placed end-to-end. The combined advantages of Subaru’s large 8.2m primary mirror and its camera at prime focus gave the researchers such a wide field of view that they could observe objects beyond their intended targets and make the surprising discovery of the emerald-shaped dwarf galaxy. Additional information gleaned from the use of green, red, and infrared filters along with the good image quality seeing in the observation enabled the researchers to see and measure a stellar disk embedded within the rectangular-shaped galaxy. The blue color of the inner disk suggested a younger average age for this stellar population.

Full Story: http://www.naoj.org/Pressrelease/2012/03/19/index.html

MoonMappers Lets Public Be Part of NASA Lunar Science

March 22, 2012 Leave a comment

Through MoonMappers, the public is offered a chance to be part of NASA Lunar Science

The MoonMappers citizen science project at CosmoQuest.org invites the public to become part of the Lunar Reconnaissance Orbiter’s science team. Through this project, the public is invited to explore high-resolution Lunar images and map out scientifically interesting features. People can get engaged at http://cosmoquest.org/moonmappers

The focus of MoonMappers is two-fold: to determine the most effective way to map craters on the moon, and to use those maps to define areas for follow-up study.

“Craters can reveal all sorts of different properties about the Moon and planetary surfaces in general,” says project co-science lead Stuart Robbins (Southwest Research Institute, Boulder). Key features include, “Ages of different regions, historic spikes in the impact rate, lunar regolith depth, what may lie under the crust, and the physics of giant explosions on a planetary surface.”

Full Story: http://cosmoquest.org/Press_Release:_MoonMappers_Goes_Public