Mars under the microscope

This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand, in this image released by NASA 's Jet Propulsion Laboratory in Pasadena, California, February 4, 2004. The image was captured on the 10th day of the rover's mission by its microscopic imager and roughly approximates the color a human eye would see. Opportunity, NASA's second of two roving Mars probes, rolled ten feet off its lander onto Mars on January 31. [NASA]

This map of a portion of the small crater currently housing NASA 's Mars Opportunity rover shows where grey hematite resides, in this image released by NASA's Jet Propulsion Laboratory in Pasadena, California, February 4, 2004. Red and orange indicate high levels of the mineral, blue and green denote low levels. The Opportunity, NASA's second of two roving Mars probes, rolled ten feet off its lander onto Mars January 31. [NASA]

This image taken by the front hazard-identification camera onboard the Mars Exploration Rover Opportunity shows the rover's arm in its extended position. The arm, or instrument deployment device, was deployed on the ninth martian day, or sol, of the mission. The rover, now sitting 1 meter (3 feet) away from the lander, can be seen in the foreground. [NASA]

This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured on the 10th day, or sol, of the rover's mission by its microscopic imager, located on the instrument deployment device, or "arm." Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or "seed." [NASA]