White Rock of Pollack Crater
January 1, 2004
The famous White Rock of Pollack Crater has been known for three decades; it was originally found in images acquired by the Mariner 9 spacecraft in 1972. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) close-up view, obtained in October 2003, shows some of the light-toned, wind-eroded sedimentary rock that makes up White Rock. It is not actually white, except when viewed in a processed, grayscale image (in color, it is more of a light butterscotch to pinkish material). The sediment that comprises White Rock was deposited in Pollack Crater a long time ago, perhaps billions of years ago; the material was later eroded by wind. Dark, windblown ripples are present throughout the scene. This picture is located near 8.2°S, 335.1°W, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.