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Mars

This undated image provided by NASA shows the Mars rover Opportunity looking back at an outcrop where it spent the Martian winter. Opportunity started driving again this week after spending 19 weeks in one spot conducting science experiments, Tuesday, May 8, 2012. (AP Photo/NASA)

NASA's Mars rover 'Opportunity'

After spending nearly five months conducting experiments in one spot, the NASA Mars rover 'Opportunity' moved for the first time the week of May 7, rolling off the rock outcrop where it hunkered down for the Martian winter.