This image shows a lesser known, but unusual feature on Mars. It is called "White Rock". The picture was made from a mosaic of 6 images acquired by the Viking 1 orbiter spacecraft on September 9, 1978. The white feature is eroded crater fill, but exactly how it was formed has not been satisfactorily explained. White Rock was not formed by polar processes because it lies near to the equator at latitude -8 degrees and longitude 355 degrees. It has been modified through aeolian erosion showing transverse and longitudinal erosional features. Future missions will be required to more fully understand the processes that formed this enigmatic formation.
This image is Copyright © 1998 by Calvin J. Hamilton. Any commercial/for-profit use of this image needs to be addressed to Calvin J. Hamilton.