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Posts Tagged ‘Vesta’

Protoplanet Vesta: Forever Young?

November 4, 2012 Leave a comment

Vesta, as seen by Dawn. Credit: NASA/JPL-Caltech/UCLA/MPS
/DLR/IDA/Brown

Like a movie star constantly retouching her makeup, the protoplanet Vesta is continually stirring its outermost layer and presenting a young face.

New data from NASA’s Dawn mission show that a common form of weathering that affects many airless bodies like Vesta in the inner solar system, including the moon, surprisingly doesn’t age the protoplanet’s outermost layer. The data also indicate that carbon-rich asteroids have been splattering dark material on Vesta’s surface over a long span of the body’s history.

Over time, soils on the moon and on asteroids have undergone extensive weathering. Scientists see this in the accumulation of tiny metallic particles containing iron, which dulls the bright, fluffy outer layers of these bodies. Yet Dawn’s visible and infrared mapping spectrometer (VIR) and framing camera detected no accumulation of these tiny particles on Vesta, and the protoplanet (sometimes called a giant asteroid) remains bright and pristine.

Full Story: http://newsroom.ucla.edu/portal/ucla/protoplanet-vesta-forever-young-240211.aspx
Also: http://www.jpl.nasa.gov/news/news.php?release=2012-342

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

Vesta Likely Cold and Dark Enough for Ice

January 25, 2012 Leave a comment

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Though generally thought to be quite dry, roughly half of the giant asteroid Vesta is expected to be so cold and to receive so little sunlight that water ice could have survived there for billions of years, according to the first published models of Vesta’s average global temperatures and illumination by the sun.

“Near the north and south poles, the conditions appear to be favorable for water ice to exist beneath the surface,” says Timothy Stubbs of NASA’s Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland, Baltimore County. Stubbs and Yongli Wang of the Goddard Planetary Heliophysics Institute at the University of Maryland published the models in the January 2012 issue of the journal Icarus. The models are based on information from telescopes including NASA’s Hubble Space Telescope.

Vesta, the second-most massive object in the asteroid belt between Mars and Jupiter, probably does not have any significant permanently shadowed craters where water ice could stay frozen on the surface all the time, not even in the roughly 300-mile-diameter (480-kilometer-diameter) crater near the south pole, the authors note. The asteroid isn’t a good candidate for permanent shadowing because it is tilted on its axis at about 27 degrees, which is even greater than Earth’s tilt of roughly 23 degrees. In contrast, the moon, which does have permanently shadowed craters, is tilted at only about 1.5 degrees. As a result of its large tilt, Vesta has seasons, and every part of the surface is expected to see the sun at some point during Vesta’s year.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2012-024

Dawn Obtains First Low Altitude Images of Vesta

December 21, 2011 Leave a comment

 Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

NASA’s Dawn spacecraft has sent back the first images of the giant asteroid Vesta from its low-altitude mapping orbit. The images, obtained by the framing camera, show the stippled and lumpy surface in detail never seen before, piquing the curiosity of scientists who are studying Vesta for clues about the solar system’s early history.

At this detailed resolution, the surface shows abundant small craters, and textures such as small grooves and lineaments that are reminiscent of the structures seen in low-resolution data from the higher-altitude orbits. Also, this fine scale highlights small outcrops of bright and dark material.

A gallery of images can be found online at: http://www.nasa.gov/mission_pages/dawn/multimedia/gallery-index.html .

The images were returned to Earth on Dec. 13.  Dawn scientists plan to acquire data in the low-altitude mapping orbit for at least 10 weeks. The primary science objectives in this orbit are to learn about the elemental composition of Vesta’s surface with the gamma ray and neutron detector and to probe the interior structure of the asteroid by measuring the gravity field.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-391

NASA’s Dawn Spirals Down to Lowest Orbit

December 12, 2011 Leave a comment

Image credit: NASA/JPL-Caltech

Image credit: NASA/JPL-Caltech

NASA’s Dawn spacecraft successfully maneuvered into its closest orbit around the giant asteroid Vesta today, beginning a new phase of science observations. The spacecraft is now circling Vesta at an altitude averaging about 130 miles (210 kilometers) in the phase of the mission known as low altitude mapping orbit.

“Dawn has performed some complicated and beautiful choreography in order to reach this lowest orbit,” said Marc Rayman, Dawn chief engineer and mission manager based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We are in an excellent position to learn much more about the secrets of Vesta’s surface and interior.”

Launched in 2007, Dawn has been in orbit around Vesta, the second most massive object in the asteroid belt between Mars and Jupiter, since July 15. The team plans to acquire data in the low orbit for at least 10 weeks.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-384

New NASA Dawn Visuals Show Vesta’s ‘Color Palette’

December 6, 2011 Leave a comment

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Vesta appears in a splendid rainbow-colored palette in new images obtained by NASA’s Dawn spacecraft. The colors, assigned by scientists to show different rock or mineral types, reveal Vesta to be a world of many varied, well-separated layers and ingredients. Vesta is unique among asteroids visited by spacecraft to date in having such wide variation, supporting the notion that it is transitional between the terrestrial planets — like Earth, Mercury, Mars and Venus — and its asteroid siblings.

In images from Dawn’s framing camera, the colors reveal differences in the rock composition associated with material ejected by impacts and geologic processes, such as slumping, that have modified the asteroid’s surface. Images from the visible and infrared mapping spectrometer reveal that the surface materials contain the iron-bearing mineral pyroxene and are a mixture of rapidly cooled surface rocks and a deeper layer that cooled more slowly. The relative amounts of the different materials mimic the topographic variations derived from stereo camera images, indicating a layered structure that has been excavated by impacts. The rugged surface of Vesta is prone to slumping of debris on steep slopes.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-375

Asteroids, Mars and Drought Among NASA News Highlights at American Geophysical Union Meeting

December 2, 2011 Leave a comment

NASA researchers will present new findings on a wide range of Earth and space science topics at the 2011 fall meeting of the American Geophysical Union. The meeting takes place Dec. 5-9 at the Moscone Convention Center, 747 Howard St., in San Francisco. Media registration for the event is open.

Media briefings during the meeting will feature topics such as new results about the asteroid Vesta, the future risk of major droughts, new discoveries at the edge of our solar system, and the 2011 Japanese tsunami. In addition, NASA scientists and their colleagues who use NASA research capabilities will present noteworthy findings during scientific sessions that are open to registered journalists.

Full Story: http://www.nasa.gov/home/hqnews/2011/nov/HQ_M11-242_AGU_Media_Events.html