Niezwykłe wydmy na Marsie

Scientists have dsicovered a series of unusual circles on Mars. The "almost perfectly circular" sand dunes were spotted on the Red Planet by cameras aboard a NASA spacecraft. While sand dunes may be quite common on Mars, it is strange for them to form circles which are nearly exact, said geologist Alfred McEwen, who has been examining the photo from NASA's Mars Reconnaissance Orbiter (MRO). The shapes were spotted by the HiRISE camera, the most powerful ever sent to another planet which is on NASA's MRO, as scientists were examining how frost thaws at the end of a Martian winter. "Sand dunes of many shapes and sizes are common on Mars. In this example, the dunes are almost perfectly circular, which is unusual," wrote Mr McEwen, of the University of Arizona, where the HiRISE camera is operated. "They are still slightly asymmetrical, with steep slip faces on the south ends. This indicates that sand generally moves to the south, but the winds may be variable. "This is part of a series of images to monitor how frost disappears in the late winter; this observation appears to be free of frost. A previous image shows when the surface was covered by frost." A previous image shows when the surface was covered by frost. Mars Reconnaissance Orbiter has been orbiting and studying Mars since 2006. The spacecraft is designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. When: 16 Mar 2023 Credit: NASA/JPL-Caltech/University of Arizona/Cover Images **EDITORIAL USE ONLY. MATERIALS ONLY TO BE USED IN CONJUNCTION WITH EDITORIAL STORY. THE USE OF THESE MATERIALS FOR ADVERTISING, MARKETING OR ANY OTHER COMMERCIAL PURPOSE IS STRICTLY PROHIBITED. MATERIAL COPYRIGHT REMAINS WITH NASA.**