English: This mosaic 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."