Seasonal Changes of Polar Megadunes

This image covers a unique polar dune field during northern spring, revealing some interesting patterns. The main "megadune" formation comprises giant crescent-shaped dunes called "barchans," which have been migrating (from upper-right to lower-left) over the past several centuries or more. Light-toned seasonal carbon dioxide frost and ice that accumulated over the winter still covers the majority of the surface, and is now starting to defrost and sublimate in complex patterns.