July 18, 2016

Where we have been

A Piece of Mars: This 0.98×0.54 km (0.61×0.34 mi) scene shows ancient windblown bedforms (maybe dunes) that have been partially eroded by the wind. The wind has left behind ghostly stripes: these are remnants of where these things once were, […]
May 23, 2016

Dune cannibals II

A Piece of Mars: This 0.96×0.54 km (0.60×0.34 mi) scene shows two sets of bedforms (dunes), each aligned in different directions. The more closely-spaced set has sharper crests, and it’s superposed on top of (and it is therefore younger than) […]
May 16, 2016

Wind shadow

A Piece of Mars: There’s a dune field migrating past a 230 m (755 ft) diameter crater, creating a 1.6 km (1 mi) long “shadow” that’s empty of dunes. Why? The rim of the crater pokes up just enough to […]
April 25, 2016

Old ripples

A Piece of Mars: In this 480×270 m scene (0.3×0.17 mi), there are a bunch of “ripples” spaced by 5-20 m (the quotes are because we don’t know yet if these are ripples, dunes, or some other new kind of […]
April 11, 2016

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 […]
April 4, 2016

The wind paints

A Piece of Mars: For the last few billion years, the wind has (by far) moved more sediment around on Mars than any other geological process. Not tectonics, volcanism, fluvial activity, or impact cratering (although a case has been made […]
March 7, 2016

How far does the wind blow stuff?

A Piece of Mars: Hargrave crater has an amazing array of colorful surfaces, each of which reflects a different type of rock (this scene is 480×270 m or 0.3×0.17 mi). I like the ripples sitting on top of it all; […]
February 20, 2016

It’s a rock-eat-rock world

A Piece of Mars: This 738 x 415 m (0.46 x 0.26 mi) scene shows dark sand flowing down a channel bisected by a ~60 m (~200 ft) tall, thin “island”. That island, and many others around it (see the […]
January 25, 2016

Remnants of erosion

A Piece of Mars: The gray area in the center of the 480×270 m (0.3×0.17 mi) area is an erosional remnant: once, more of this area was covered by the gray stuff, but some of it has eroded away (most […]