When dunes are located in a complex topographical area such a canyon, they become ideal candidates for detecting changes to their shapes and sizes over time.
The dunes here in Ganges Chasma–a canyon that’s on the eastern end of Valles Marineris–could be strongly influenced by winds , and it’s important not to underestimate the erosional power of wind. Because HiRISE has such good resolution, we can track these changes over time to tell us which way a dune is moving, how much, and in what direction. From these observations we can decipher present-day atmospheric processes.
Written by: HiRISE Science Team (audio by Tre Gibbs) (9 May 2012)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_026100_1725
Image: NASA/JPL/University of Arizona