The dunes in Gale Crater on Mars, near the landing site of the Curiosity rover, are moving. Until a few years ago, it was thought that the surface of Mars was largely inactive, with its landscapes no longer undergoing any significant modification. The identification of widespread active sand dune migration is one of several recent discoveries that has disproved this claim. A recent paper by Simone Silvestro of the SETI Institute and colleagues demonstrates that sand dunes in Gale crater, located between the Curiosity rover and its final destination, Aeolis Mons (“Mount Sharp”), are among the actively migrating dunes on Mars.
These dunes are moving towards the southwest at a rate of 0.4 meters per Earth year (an average of just over 1 mm per day). This indicates that the work of the wind is probably the most important process currently shaping the landscape in Gale crater. The images used in this study are from the High Resolution Imaging Science Experiment (HiRISE), the camera onboard the Mars Reconnaissance Orbiter.
|Dune migration in the SW sector of the dune field at the base of Aeolis Mons (Mt. Sharp). Data source: High Resolution Imaging Science Experiment (HiRISE) NASA/JPL/University of Arizona|
Two main wind patterns have formed the dunes: winds from the northwest, and winds from the northeast. The northeasterly wind has most significantly changed the dunes and ripples in the last few years near a potential path of Curiosity. An atmospheric model, the Mars Regional Atmospheric Modeling System (MRAMS), produces wind predictions that support both of these findings.
|Color-enhanced view of the terrain and dunes ~1-2 km southwest from the Curiosity landing site in Gale Crater, Mars. Data source: HiRISE, NASA/JPL/University of Arizona.|
The Curiosity rover must pass through this dune field on its traverse up the mountain, and it is likely that the rover will be able to see these dunes in action as it drives by them. These observations will be the first in situ study of dune migration on another world in the Solar System.