December

December 31, 2012

Dune cannibals

A piece of Mars: Dunes often cannibalize each other, with new dunes forming from the sand in older dunes. Here the tan dunes have formed from the sand that made up the grayish blue dunes. Notice the banding on the […]
December 19, 2012

Bye-bye, crater

A piece of Mars: On Earth, it’s typically water that erodes a landscape, as rivers cut down rocks, storms trigger landslides, and ocean waves eat away at shorelines. On Mars, it’s usually the wind that slowly grinds down a landscape. […]
December 16, 2012

Wisps

A piece of Mars: These wispy dunes look like veins on a leaf, don’t they? The thicker ones are older, and they are slowly being reworked by the younger, thinner ones. If they remain active, then the smaller ones will […]
December 11, 2012

The Painted Desert, on Mars

A piece of Mars: Small dunes or ripples in a depression provide a striking contrast with the surrounding bedrock. The sand in the dunes changes color, too, to mark off which regions have more recently been actively moved by the […]
December 6, 2012

Crescents and ripples

A piece of Mars: A lonely dune slowly makes its way (towards the upper right) across a plain. Well, look closer, it’s not all that lonely. Surrounding it on the plain are smaller streaks that are ripples, which also once […]