Sand Dunes Near the North Pole of Mars
These dark sand dunes in the North polar region, basking in the sunshine of late spring, have shed most of their seasonal layer of winter ice. A few bright ice deposits remain sequestered in "cold traps" shadowed from the sun on the poleward-facing side of the dunes.
Some bright patches of ice at the foot of the sunlit side of the dunes may be places where ice slumped to the foot of the dune creating a longer-lasting snow bank. Larger image.