This color image taken by the panoramic camera onboard the Mars Exploration Rover Opportunity shows the part of the rock outcrop dubbed Stone Mountain at Meridiani Planum, Mars. Scientists are examining Stone Mountain with the instruments on the rover's instrument deployment device, or "arm," in search of clues about the composition of the rock outcrop.

A Patch of Stone (Figure credit: NASA/JPL/Cornell/USGS)

The colorless square in this color image of the martian rock formation called Stone Mountain is one portion of the rock being analyzed with tools on the Mars Exploration Rover Opportunity's instrument deployment device, or "arm." The square area is approximately 3 centimeters (1.2 inches) across. Stone Mountain is located within the rock outcrop on Meridiani Planum, Mars. The image was taken by the rover's panoramic camera.