A large dune field, still partially covered with seasonal carbon dioxide frost, shows evidence of movement of dune material. When the changes took place is not known.
Channels carved on face of dunes are visible in this subimage. . Rather than going straight down the dune, the channels zigzag back and forth. The fluid or gas that carved the channel is an enigma. Older channels are filled in and ripples are visible there.
Written by: Candy Hansen (21 January 2009)
More info and image formats at http://hirise.lpl.arizona.edu/PSP_010749_1325
Image: NASA/JPL/University of Arizona