Martian sand blowing in the wind

Abstract

High-resolution spacecraft images show surprisingly large rates of sand transport on Mars. This finding suggests that the planet's surface is a more active environment than previously thought. See Letter p.339 There is clear evidence for wind erosion and dune formation on the surface of Mars, but the extent of these movements and whether the processes are current have remained unclear. Analysing data from the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter, Bridges et al. measure the migration of sand ripples across the Nili Patera dune field in the Martian southern hemisphere. They find that the dunes have surprisingly large sand fluxes, equivalent to those seen in extreme desert conditions on Earth. One view of Mars has been that conditions since the end of the Hesperian period (between 1.8 billion and 3.5 billion years ago) have been fairly static, with very low erosion rates, but these findings suggest that in parts of Mars at least, there are strong gusts of sand and wind still making themselves felt.