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2012-09-20. NASA Dawn Spacecraft Sees Hydrated Minerals on Giant Asteroid

posted Sep 23, 2012, 3:55 PM by Alan Gould
| by NASA Release 12-334. An article relevant to GSS A Changing Cosmos chapter 7. Excerpt:  WASHINGTON -- NASA's Dawn spacecraft has revealed the giant asteroid Vesta has … volatile, or easily evaporated, materials … in a broad swath around its equator. ... Pothole-like features mark some of the asteroid's surface where the volatiles boiled off. Dawn … found evidence of hydrated minerals delivered by meteorites and dust in the giant asteroid's chemistry and geology. The findings appear Thursday in the journal Science. "The source of the hydrogen within Vesta's surface appears to be hydrated minerals delivered by carbon-rich space rocks that collided with Vesta at speeds slow enough to preserve their volatile content," said Prettyman. …Scientists thought it might be possible for water ice to survive near the surface around the giant asteroid's poles. Unlike Earth's moon, however, Vesta has no permanently shadowed polar regions where ice might survive. The strongest signature for hydrogen in the latest data came from regions near the equator, where water ice is not stable….Escaping water left holes as much as six-tenths of a mile (1 kilometer) wide and as deep as 700 feet (200 meters). Seen in images from Dawn's framing camera, this pitted terrain is best preserved in sections of Marcia crater. …To view new images and for more information about Dawn, visit: http://www.nasa.gov/dawn . Read the full article: http://www.nasa.gov/home/hqnews/2012/sep/HQ_12-334_Dawn_Minerals.html