Martian Blueberries

The left image shows an extreme close-up of round, blueberry-shaped formations in the martian soil near a part of the rock outcrop at Meridiani Planum called Stone Mountain. Scientists are studying these curious formations for clues about the area's past environmental conditions. The image, one of the highest resolution images ever taken by the microscopic imager, an instrument located on the Mars Exploration Rover Opportunity's instrument deployment device or "arm."

This sharp, close-up image on the right was taken by the microscopic imager on the Mars Exploration Rover Opportunity's instrument deployment device, or "arm," shows a rock target dubbed "Robert E," located on the rock outcrop at Meridiani Planum, Mars. Scientists studied the spherule, or small sphere, in the center of the image that appears to be protruding from the rock formation. This image measures 3 centimeters (1.2 inches) across and was taken on the 15th day of Opportunity's journey (Feb. 8, 2004). See full image at http://photojournal.jpl.nasa.gov/catalog/PIA05238 .