This image was taken by the Mars Exploration Rover Spirit's panoramic camera during the rover's grinding of the rock dubbed "Mazatzal" with its rock abrasion tool. The picture shows the untouched rock on sol 78, which is covered in a light-toned coating and red dust particles. This approximate true-color image was created using the panoramic camera's red, green and blue filters.
Image credit: NASA/JPL/Cornell
