One benefit of MRO’s extended missions is the chance to see landscapes change over time.

These barchan sand dunes are a case in point: these have been imaged at least five times already, and each time, a bit more movement is revealed.

The steeply-dipping slip faces (where sand slides down after it gets piled up on the dunes’ crests) indicate the direction of the wind, although this particular dune field seems to show *two* converging wind directions.

ID: ESP_043617_1885
date: 16 November 2015
altitude: 276 km

https://uahirise.org/hipod/ESP_043617_1885
NASA/JPL-Caltech/UArizona
#Mars #science #NASA