Soft Rock Yields Clues to Mars' Past This image taken by the Mars Exploration Rover Spirit shows the rock outcrop dubbed "Clovis." The rock was discovered to be softer than other rocks studied so far at Gusev Crater after the rover easily ground a hole into it with its rock abrasion tool. An analysis of the interior of the hole with the rover's scientific instruments found higher concentrations of sulfur, bromine and chlorine compared to basaltic, or volcanic, rocks at Gusev. This might indicate that Clovis was chemically altered, and that fluids once flowed through the rock depositing these elements. Spirit's solar panels can be seen in the foreground. This image was taken by the rover's navigation camera on sol 205 (July 31, 2004). Release Date: 8/18/04 Image Credit: NASA/JPL Reference URL: http://photojournal.jpl.nasa.gov/catalog/PIA06771 + Return to previous page