The Physics of Sand Dune Formation and Migration on Mars

Sand dunes have been observed throughout the surface of the planet Mars. Movement of these dunes has been theorized and inferred from the lack of craters on dunes. Dune movement has not yet been directly imaged, however. Understanding sand movement processes is vital to a correct Martian climate model, as well as the safety of future missions to Mars. Imagery from several Martian orbiters was analyzed in an attempt to discern movement of Martian sand dunes. Additional imagery from Mars Exploration Rover Opportunity was analyzed to search for evidence of dune movement or saltation at Meridiani Planum, Mars. Data from Opportunity shows that a saltation event occurred sometime in July 2007, at the rim of Victoria Crater. No dune movement was detected, suggesting that dune movement, if it occurs on Mars, is on the scale of centimeters or less per Martian year. Future studies should benefit from added high-resolution satellite imagery, which is currently being collected by the Mars Reconnaissance Orbiter, and, if current theories on dune movement are correct, dune movement should be discernable within a few years.