NASA's Mars Exploration Rover Opportunity used its front hazard-avoidance camera to take the picture above showing the rover's arm extended toward a light-toned rock, "Tisdale 2," during the 2,695th Martian day, or sol, of the rover's work on Mars (Aug. 23, 2011). Tisdale 2 is about 12 inches (30 centimeters) tall. Opportunity arrived three weeks ago at the rim of a 14-mile-wide (22-kilometer-wide) crater named Endeavour. The first rock it examined is flat-topped and about the size of a footstool. It was apparently excavated by an impact that dug a crater the size of a tennis court into the crater's rim. The rock was informally named "Tisdale 2."...
read more>>>...
