Category: Uncategorized
Topography and the wind
A piece of Mars: Everybody else loves this image because it shows an inverted channel -- the remains of a stream that once flowed through this area. But I love it because the little dunes were also formed by a ...
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 ...
Almost a dune
A piece of Mars: Not all piles of windblown sand are able to form proper dunes, with a fully developed avalanche on the downwind side. Here, bluish sand tries to make its way through hilly terrain, which both traps the ...
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 ...
Drifting sand
A piece of Mars: Dark sand has been blown into the scene from the upper right. It has piled up against older, brighter dunes that may now be inactive. The sand drifts on and on, piling up where the wind ...
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 ...
Rainbow dunes on Mars
A piece of Mars: The dark dune here seems to have a subtle rainbow color across it. Is it a real rainbow? Well, no. Part of it is that I've stretched the image to enhance color, so the dark dune ...
Dunes being buried
A piece of Mars: Most dunes on Mars are the freshest, youngest features around. Not so here. The bright dunes near the bottom here are slowly being buried by debris coming down from the gullies on the slope, coming from ...
Bright and dark sand on a dune
A piece of Mars: A lovely little dune is right at the edge of this image, trying its best to migrate into the center of the frame. The bright sickle-shaped part of the dune is its slip face, where sand ...
Crescents and ripples
A piece of Mars: A lonely dune slowly makes its way (towards the upper right) across a plain. Well, look closer, it's not all that lonely. Surrounding it on the plain are smaller streaks that are ripples, which also once ...