This undated image provided by NASA's Dawn spacecraft on Dec. 27,2011 showing a close-up view of a huge crater in the southern hemisphere of the Vesta asteroid. A recent analysis of images taken by ... more 
This undated image provided by NASA's Dawn spacecraft on Dec. 27,2011 showing a close-up view of a huge crater in the southern hemisphere of the Vesta asteroid. A recent analysis of images taken by the Dawn spacecraft reveals there are two overlapping craters in Vesta's south pole created by separate impact events. (AP Photo/NASA) less 
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Associated Press | Photo By NASA
Thu, May 10, 2012 3:26 PM EDT