Kaiser Crater Dunes

This VIS image is located in Kaiser Crater and shows a dune field on the crater floor. The crater floor is visible between the dunes, indicating that there is a limited sand supply creating the dunes. Local winds continue to move the sand dunes across the crater floor. There are two sides to a dune, the low angle slope of the windward face and the high angle slope of the leeward side. The steep side is called the slip face. Wind blows sand grains up the low angle slope of the dunes which then "fall down" the slip face. In this way the whole dune moves towards the slip face. The winds blow from the windward to the leeward side of the dunes. In this image the slip faces are on the left side of the dune, so the dunes are slowly moving to the left side of this image. Kaiser Crater is 207 km (129 miles) in diameter and is located in Noachis Terra west of Hellas Planitia.