Tag Archives: aeolian

Dune cannibals II

A Piece of Mars: This 0.96x0.54 km (0.60x0.34 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) ...

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 ...

Old ripples

A Piece of Mars: In this 480x270 m scene (0.3x0.17 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 ...

Windy windows

A Piece of Mars: Here's a tiny bit (0.69x0.39 km or 0.43x0.24 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 ...

Three types of windblown piles of stuff

A Piece of Mars: The wind blows different sorts of sediment in different ways. Ultimately they pile up because some oddity in nature makes one spot accumulate more sediment than other spots, allowing that windblown pile of stuff to grow. ...

Dune shadows

A Piece of Mars: Normally I post in color, but sometimes you need to back out to the grayscale images to see the big awesome things. This scene is 4.6x2.6 km (2.8x1.6 mi); the conical hill is 1.4 km (0.89 ...

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 480x270 m or 0.3x0.17 mi). I like the ripples sitting on top of it all; ...

Remnants of erosion

A Piece of Mars: The gray area in the center of the 480x270 m (0.3x0.17 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 ...

That which curves and that which is straight

A Piece of Mars: The long meandering lines snaking across the image (3.2x1.8 km or 2x1.1 mi across) are inverted channels. They are river deposits that once were the lowest part of the landscape (rivers always are), but then the ...

Curiosity about sand dunes (part 1/2)

Sorry for the pun in the title there, but NASA asked for it by naming their rover like that. And you've seen it done a hundred times, so let's grit our teeth, smile, and carry on. Anyway. So I'm more excited now ...