Image: NASA / JPL-Caltech / University of Arizona
Scientists at Arizona state University (USA) found on Mars, the processes that do not have analogues on Earth. These include relatively rapid movement of sand dunes in conditions of the rarefied atmosphere. This publication reports Science Alert.
The researchers tracked the changes in 54 dune fields, covering 495 individual dunes ranging in height from two to 120 meters. To do this, they analyzed images taken by the HiRISE camera on the spacecraft Mars Reconnaissance Orbiter over the Martian 2-5 years.
It turned out that the average migration speed of the dunes in the shape of a Crescent was only half a meter a year, about 50 times slower than the fastest dunes on Earth. However, in some places the movement was most rapid in the Large Sirte, the mountain chain of the Hellespontus Montes and Subpolar sandy areas of the Olympia Undae and Abalos. These areas are characterized by a sharp topographic boundaries and temperature gradients.
On the Ground at the speed of dunes is influenced by completely different factors. For example, groundwater near the surface and vegetation cover slow the movement of sand. Another Martian feature, occurring less frequently, were sandy plains with high albedo. They reflect a lot of sunlight, heat the air and create convection currents that move the sand.
Video, photo All from Russia.