Nasa spacecraft detects changes in Martian sand dunes
NASA’s Mars Reconnaissance Orbiter has revealed that movement in sand dune fields on the Red Planet occurs on a surprisingly large scale, about the same as in dune fields on Earth. This is unexpected because Mars has a much thinner atmosphere than Earth, is only about one percent as dense, and its high-speed winds are less frequent and weaker than Earth’s.
For years, researchers debated whether sand dunes observed on Mars were mostly fossil features related to past climate, rather than currently active. In the past two years, researchers using images from Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera have detected and reported sand movement.
Now, have determined that entire dunes as thick as 61 meters are moving as coherent units across the Martian landscape. The study adds important information about the pace at which blowing sand could be actively eroding rocks on Mars. Scientists estimate rocks would be worn away at about the same pace as rocks near sand dunes here on Earth in Antarctica, where similar sand fluxes occur.
Above: Back-and-forth blinking of these two-image animations, taken in a period of three Earth years, shows movement of a sand dune in Nili Patera on Mars.