Barchan Dunes on Mars and Earth

Barchan Dunes are simply well-ordered piles of sand with a characteristic horseshoe-like shape, which can migrate across vast distances and coalesce into flowing ridges. Here are two examples of these dunes - one from southern Mars and one from southern Earth. Can you guess which picture is from where?

Image source: APOD

Image source: Google

See also: Optical Illusion - "Shifting Almonds"