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shadow on MarsNASA's robotic space explorers, the Mars rovers Spirit and Opportunity, have done the unexpected by surviving for a full Martian year (687 Earth days) on the red planet. When Spirit first landed on Jan. 3, 2004, scientists hoped that the rovers would last 90 sols, or Martian days.
Spirit's shadow and robotic arm are captured in this image. In early December 2005, researchers reported that Opportunity's robotic arm may be permanently damaged.