Meridiani Planum at the northern edge of the Southern Highlands of Mars. In the centre of the image, the floor of an impact crater almost 50 kilometres wide is covered in dark material that resembles volcanic ash. Small mounds, probably composed of more resistant material, are visible protruding through the dark material. The softer material around them has been eroded and blown out of the crater by northeasterly winds forming dark streaks on the surroundings (top left of the image).
Credits: ESA/DLR/FU Berlin (G. Neukum).