Martian rock. Colour image of part of a bedrock outcrop on Mars. Numerous spherical particles can be seen in the soil surrounding the rock. These may have been formed from molten rock sprayed into the air by a volcano or meteorite impact, or by the accretion in water of successive mineral layers around a smaller particle. The spheres are gradually being released from the rock as it is eroded by windblown sand. This image was taken by the panoramic camera on the Mars Exploration Rover Opportunity. For a colour-enhanced version of the same image, see R360/129, and for a microscopic image of a portion of the bedrock see R360/130.