This NASA image received 19 March 2004 s

WASHINGTON, UNITED STATES: This NASA image received 19 March 2004 shows an overhead view of the Mars Exploration Rover Opportunity landing site at Meridiani Planum, nicknamed "Eagle Crater." Scientists are conducting a soil survey here to see how the soils in this crater relate to the soils by the Meridiani Planum rock outcrop, as well as on the plains outside the crater. They have studied the soils in great detail on the north and west sides of the crater. Locations within the crater where scientists have taken microscopic images of the soil are shown in blue. AFP PHOTO/NASA/JPL/Ames/Cornell/ Washington University (St. Louis) (Photo credit should read HO/AFP via Getty Images)