Tag Archives: erosion

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 ...

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 ...

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; ...

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 ...

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 ...

Windy windows

A Piece of Mars: This 0.96x0.54 km (0.6x0.33 mi) area shows ripples forming on a layer of dark gray material. In a few spots, the gray layer has been eroded away (probably by wind scour), revealing the lighter, tan-colored ...

Layered winds

A piece of Mars: On the left is high ground, covered with dunes (or maybe they're ripples) running from upper left to lower right. On the right is low ground, covered in deeply eroded dunes (ripples?) running almost from left ...

What is burying what?

A piece of Mars: There's an egg-shaped plateau here (the whole scene is 480x270 m or 525x295 yd across, the "egg" is ~100 m long). It's partly covered by dunes that have extended across it. Or were the dunes there ...