A Piece of Mars: There’s a fabric of erosion in this 1×1 km (0.62×0.62 mi) scene, with the main wind blowing from lower right to upper left (and if you look carefully you’ll see there’s a second, subtler fabric a bit clockwise from that one). The result is a landscape strewn with streamlined rock called

A change of fluids

A Piece of Mars: Water carved this ~800 m (0.5 mi) wide channel billions of years ago. The water dried up, and since then it’s been sand that flows through here (from the right), building up lovely dunes. A single crater on one of the dunes indicates that they’re not very active (dunes of this

Dunes in a colorful hole

A Piece of Mars: Gray dunes have migrated over reddish rock, moving toward a narrowing cleft surrounded by tall tan cliffs. Bright lines on the dunes are exposed internal layers (bones of the dunes, really) that show you where the lee-side slopes once were (so you can tell they’ve moved to the left). The cliffs

Bedforms on crater rims

A Piece of Mars: Dunes and ripples most commonly form in topographic lows. But not in this 0.96×0.54 km (0.6×0.34 mi) scene. Here, and in other places on Mars, these bedforms (called TARs) form on plains, and sometimes appear to cling to the rims of craters – which are topographic highs, not lows. It’s not

The spire in Eberswalde crater

A Piece of Mars: OK, you have to bring out the red/blue glasses for this one. (Or click here if you’re missing your glasses and want the black and white version.) Eberswalde crater has some lovely layered deposits, long ago laid down by running water, and since eroded steadily by the wind. The wind leaves

Landslides unlike any on Earth

A Piece of Mars: Click on this 0.96×0.54 km (0.6×0.33 mi) scene to see it in detail. Many thin, narrow landslides have formed on these dust-coated hills. As far as I’m aware, there’s nothing like this on Earth. Inside the landslide scars, there are small dusty ripples about 1.75 m (~6 ft) in wavelength, smaller

Windy windows

A Piece of Mars: Here’s a tiny bit (0.69×0.39 km or 0.43×0.24 mi) of Jezero crater, one of the candidate landing sites for the Mars 2020 rover. On the bottom and left is high-standing volcanic terrain, former lava that flowed out on the crater floor. On the upper right is a much older deposit of

Is it windblown or not?

A Piece of Mars: This scene is 0.96×0.54 km (0.60×0.34 mi) across. There’s an old river valley running across it. The walls of the valley have been eroded and there’s a washboard pattern with a wavelength of ~6m (20 ft). When I first saw this image I thought it was exposed, tilted layers, but a

Huge wind-made cliffs

A piece of Mars: Topography in color is draped over an image of a windblown cliff. The entire shape of the landscape here was formed by wind, from the large 400 m (1312 ft) tall zigzag cliff, to the small streamlined shapes in the valley. Even the deep gorge that looks like a stream channel

Bearded hills

A Piece of Mars: Bright hills appear to be bearded (or perhaps mustached?). What’s going on? Dark sand has blown over some yellow-crested hills and settled on the downwind side, where the hill blocks enough wind that it can no longer move sand, and it all collects there in rippled drifts. (scene is 386×290 m,