NASA / JPL-Caltech / University of Arizona / Tanya Harrison
An icy crater on Mars
Mars has ice in the subsurface at high latitudes, and when new craters form there, they can expose this ice and eject it onto the surface. Until this HiRISE image, this phenomenon had only been seen on the northern plains, because the southern highlands have less dusty surfaces, making it is hard to find new craters there. This crater is on an outlier of the south polar layered deposits, a thick stack of layers near the south pole made of ice and dust. The layered deposits around here are covered with a layer of dust, but this crater shows that the cover isn't very thick. This crater also threw out debris that formed rays, including some very small secondary craters, but none of these smaller craters was large enough to excavate subsurface ice.