2 May 2004
The "White Rock" of Pollack Crater is a feature that has been known since it was first observed by Mariner 9 in 1972. It is not actually white, but is much brighter than the fields of large, dark, windblown ripples that surround it. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture provides the highest resolution view, ever, of a portion of the wind-eroded "White Rock" feature. The rock materials are believed to be the remains of sediment that once covered the floor of Pollack Crater. Wind has sculpted the light-toned material into ridges and troughs known as yardangs. This 1.5 meters per pixel (5 feet per pixel) image is located near 8.1°S, 335.2°W. It was acquired in late March 2004, is illuminated from the left/upper left, and covers an area about 3 km (1.9 mi) across.

An earlier MOC view of "White Rock" can be seen in: "White Rock" of Pollack Crater, 4 December 2000. See PIA02848 and PIA02849.