When Mars gets weird

A piece of Mars: Mars can be a strange place. This is actually a sand dune on Mars not far from the north pole. Here it’s imaged in the springtime when the dunes are still covered inĀ  bright CO2 frost, which is in turn overlain by yellowish dust that has fallen out of the atmosphere.

The millipede, rewritten

A piece of Mars: Looks like a millipede, doesn’t it? It’s something much larger and much less poisonous. It’s an ancient dune (or maybe a ripple) on Mars, that once stretched ~285 m (935 ft) from lower left to middle right. Since then it’s been nearly rewritten twice. The first time, a different wind direction

Ribbons on Mars

A piece of Mars: Bet you didn’t know there were ribbons on Mars. Long, sweeping, velvety lines, delicately frayed at the ends. These are actually ancient ripples, formed by a wind blowing from right to left. Stripes on the ripples and on the ground between them show the ancient ripple interiors, exposed by erosion. The

Lighting effects

A piece of Mars: It’s winter in the southern hemisphere, and dunes like these are covered in bright white CO2 frost. The sun is near the horizon (shining from the top of the image), so it creates stark shadows. That can make doing science tough, but it’s the best way to show off the beauty

Swoosh

A piece of Mars: What is this big swoosh? It’s a big dark dune. The dark/light striping across it is found in all of the dunes in this area, but what is it? We’re probably seeing the inside of the dune: the wind may so strong here that it erodes the highest point of the