HiRISE images

A piece of Mars: Bright dunes once marched through the depression created by a double impact. How can you tell the dunes are no longer moving? Because one of them has its own little crater sitting on it. A mobile dune would quickly erase such a distinctive feature. (HiRISE ESP_027018_1925) read more ❯

A piece of Mars: When the wind sandblasts at layered rocks, some pretty swirly patterns emerge. These are flat layers that take on a stacked wedding-cake appearance on an outcrop elongated by the wind. The direction of the stacks indicates the direction of the wind -- from upper left to lower right. (ESP_027011_1735) read more ❯

A piece of Mars: Wind streaks are a common sight on Mars. They are formed either by the wind blowing stuff away or blowing stuff in, and it can be quite difficult to tell which is which. In this case, I'm not entirely sure -- I suspect the bright orange streaks are erosional and the darker ones are depositional. The pale pink ones are a mystery to me. Regardless of how they form, they certainly indicate winds have blown from the lower right to upper left. (HiRISE ESP_027007_1690) read more ❯