Sand Avalanches in Meroe Patera

One of the major extended-mission objectives for HiRISE has been to re-image parts of the surface to look for changes. Such observations can tell us what processes are active today. This image was acquired as part of a series to look for sand movement in Meroe Patera, not far from the active sand dunes of Nili Patera. Our image shows that sand dunes are missing downwind (to the left) of a crater near the center of the observation, because sand falls into the crater and is trapped.