Tag Archives: erosion
Dunes on crater bones
A piece of Mars. The dark circle (~170 m across) in the middle of the picture is the interior of what used to be a crater. It's now almost completely eroded away, probably by the wind. Small dunes have formed ...
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 ...
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 ...
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 ...
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 770x577 m across, with each giant step about 20 m wide. Just imagine a huge concert ...
Circles
A piece of Mars: What are those dark, flat circles and why are there little dunes sitting on top of them? They're probably old impact craters that got filled in with dark sediment, and were then eroded flat. So you're ...
Mysterious textures
A piece of Mars: Dunes don't usually have a rough surface texture like these do. It's not clear what's going on. Are they ancient dunes that are being eroded? What causes this particular texture? It seems unique to high elevations ...
Dune cannibals
A piece of Mars: Dunes often cannibalize each other, with new dunes forming from the sand in older dunes. Here the tan dunes have formed from the sand that made up the grayish blue dunes. Notice the banding on the ...
Bye-bye, crater
A piece of Mars: On Earth, it's typically water that erodes a landscape, as rivers cut down rocks, storms trigger landslides, and ocean waves eat away at shorelines. On Mars, it's usually the wind that slowly grinds down a landscape. ...
Wisps
A piece of Mars: These wispy dunes look like veins on a leaf, don't they? The thicker ones are older, and they are slowly being reworked by the younger, thinner ones. If they remain active, then the smaller ones will ...