barchan
July 11, 2012
A piece of Mars: Dunes near the north pole of Mars form in a very cold environment. Winter ice continually tries to stop them in their tracks, which makes for unusually rounded dunes like these. (HiRISE ESP_027451_2635)
May 13, 2012
A piece of Mars: In nature most dunes pile on one another or strongly influence each other. But occasionally, like a perfect flower or crystal, you find a perfectly shaped dune. Here is a crescentic dune, called a “barchan”, formed […]