March 22, 2013

Dunes in the spring

A piece of Mars: Dunes near the north and south poles get cold in the winter, just like they do on Earth. Except on Mars instead of H2O ice, it’s a mix of CO2 and H2O ice (mostly CO2). In […]
March 19, 2013

Nili Patera

A piece of Mars: Nili Patera on Mars is an ancient volcano. Some of the old volcanic material has been blown into rather striking sand dunes. It is the first place where dunes were conclusively identified as actively moving. Here’s […]
March 15, 2013

Spines

A piece of Mars: Here are some old dunes that look a little like vertebrae of fossils (if you think they look like dragon spines poking out of the ground then you’re playing too many video games). The white areas […]
March 7, 2013

Almost a dune

A piece of Mars: Not all piles of windblown sand are able to form proper dunes, with a fully developed avalanche on the downwind side. Here, bluish sand tries to make its way through hilly terrain, which both traps the […]
March 3, 2013

Windswept landscape

A piece of Mars: As the wind blows sand over terrain, the grains deepen grooves in weak materials, enhancing the topography in the direction of the strongest wind. Here, over eons, sand marching from right to left has formed dunes […]
February 22, 2013

Those feathery bright dunes on Mars

A piece of Mars: Some of the dunes on Mars are just plain weird. Here are some feather-shaped ones. I’m not sure anybody knows why they form these fractal shapes just yet. I don’t know of anything on Earth that […]
February 19, 2013

Drifting sand

A piece of Mars: Dark sand has been blown into the scene from the upper right. It has piled up against older, brighter dunes that may now be inactive. The sand drifts on and on, piling up where the wind […]
February 12, 2013

Mars’ giant amphitheater

A piece of Mars: Sandwiched between hills, a huge stepped amphitheater has been carved out of the rock by the wind. The scene is 770×577 m across, with each giant step about 20 m wide. Just imagine a huge concert […]
February 10, 2013

Rainbow dunes on Mars

A piece of Mars: The dark dune here seems to have a subtle rainbow color across it. Is it a real rainbow? Well, no. Part of it is that I’ve stretched the image to enhance color, so the dark dune […]