3 February 2004
Wind is the chief agent of change on Mars today. Wind blows dust and it can move coarser sediment such as sand and silt. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows bright ripples or small dunes on the floors of troughs northeast of Isidis Planitia near 31.1°N, 244.6°W. The picture covers an area 3 km (1.9 mi) wide; sunlight illuminates the scene from the lower left.