Mars dune with gullies in the Matara crater. The erratic course is probably due to disturbances such as wind ridges in the sand bed, sending the blocks in a different direction each time. Pits at the bottom of the slope mark the end of the process. Credit: Image taken by HiRISE (ESP_030528_1300_RED), NASA/JPL/University of Arizona. Did life really exist on Mars after all? Unfortunately, there is no conclusive evidence for this yet. Nevertheless, it would seem that some form o