Description
This mosaic of four images from the microscopic imager on NASA's Mars Exploration Rover Opportunity shows the freshly exposed interior of a rock dubbed "Lion Stone" after the rover's rock abrasion tool ground away a circular patch of the rock's surface. The circle is 45.5 millimeters (1.8 inches) in diameter. Opportunity took the images during its 108th sol (martian day) on Mars, on May 13, 2004.
