The mosaic was created from two images taken on 7 December 2005 and 9 January 2014, and focuses on the 108 km-wide Rabe crater. The region is 320 km to the west of the large Hellas impact basin, about halfway between the planet’s equator and south pole.

Wind-sculpted dunes and impact craters are common features on Mars but here we can see them combined, creating a stunning vista.

Rabe crater has an interesting topography: its flat floor has a number of smaller craters and large sunken pits within it. The bulk of the dune material sits atop the flat remnant of the original crater floor, but then some of it spills dramatically down into the pits below.

The dunes stand some 150-200 m tall and their swirling patterns indicate the prevailing direction of the winds that have whipped across the crater over time.

The dunes are made of basaltic material, a common volcanic rock that was deposited widely across Mars in the past. In the region shown here, it was subsequently covered over by other layers of material, uncovered by erosion within the crater itself.

Zooming in on the western (top in the main colour image) portion of the crater reveals distinct layers of dark material exposed in the crater walls. One possible interpretation is that the impact crater punched through the top surface to reveal these otherwise hidden layers. Over time, this material has been eroded and swept up by wind to form the dunes seen towards the centre of the crater.