Many types of dunes are found in the north circumpolar dunefield. Shown are a field of transverse dunes (left side), a field of barchan dunes (right side), and a zone of transition between them. Transverse dunes are long, linear dunes, oriented perpendicular to the prevailing wind direction, that commonly join with their neighbor in low-angle “Y” junctions. Barchan dunes are crescent-shaped mounds with downwind-pointing horns. The martian dunes are comparable in size to the largest of their terrestrial counterparts.
Location: Latitude 78°, Longitude 49°. Viking orbiter photograph 058B28, NGF rectilinear version, clear filter.