erosion

July 31, 2015

What is burying what?

A piece of Mars: There’s an egg-shaped plateau here (the whole scene is 480×270 m or 525×295 yd across, the “egg” is ~100 m long). It’s partly covered by dunes that have extended across it. Or were the dunes there […]
April 29, 2015

Wind stripes

A piece of Mars: Yes, I post a lot of pictures of martian dunes with striped patterns. They’re all distinct and beautiful. So here’s another one, 480×270 m (0.3×0.17 mi) in size. These beasts moved from right to left across […]
March 18, 2015

Melty dunes

A Piece of Mars: With all due apologies to followers of the show Coupling, I have to call these things “melty dunes”. This link shows what a crisp dune should look like. The dunes in this 600×450 m (0.37×0.28 mi) […]
January 21, 2015

Wind eroded mantle

A piece of Mars: The curving ridge of a mountain has signs of many small landslides. Mantled on top of these is an older set of landslides that has been partially eroded away. The rippled edge of this older deposit […]
January 12, 2015

Bearded craters and dunes

A piece of Mars: This 600×450 m (1969×1476 ft) scene has a complex sedimentary history. How are bearded craters and dunes formed? They weren’t always bearded. At some point, a deposit of bright material accumulated on this surface, and was […]
December 1, 2014

Inverted crater

A piece of Mars: This circular hill is 200 m (~656 ft) across and ~48 m (~160 ft) high. It stands alone on a relatively flat plain. Why is it there? The surface here used to be ~48 m higher […]
November 17, 2014

Textured gullies

A piece of Mars. These are gullies on a martian hillside (upslope is to the upper right). Water may be what forms the channels, carrying soil and rocks downslope. The textured pattern of the lower slope is caused by the […]
November 7, 2014

Rivers of freezing gas

A piece of Mars: This 600×450 m (1969×1476 ft) polar scene shows sinuous channels 2-8 m (7-26 ft) wide carved out of ice-filled and ice-covered terrain. They’re not formed by flowing water, but instead by flowing gas that gets trapped […]
October 15, 2014

Huge wind-made cliffs

A piece of Mars: Topography in color is draped over an image of a windblown cliff. The entire shape of the landscape here was formed by wind, from the large 400 m (1312 ft) tall zigzag cliff, to the small […]
September 15, 2014

Missing bedrock

A piece of Mars: Wind flow on Mars can be quite dramatic. Here, a single wind-sculpted hill stands 1.5 km (0.93 mi) wide and 600 m (1970 ft) high (color shows elevation). That sounds big, but vastly larger is the […]
September 8, 2014

Martian waves

A piece of Mars: The swirly candy stripes in these big dark dunes are layers inside that have been made visible by wind erosion (the scene is 1.5×0.9 km, or 0.93×0.56 mi). It’s rare to see the inside structure of […]
September 3, 2014

Holes around rocks

A piece of Mars: This scene (509×382 m, or 1670×1253 ft), aside from showing some lovely rippled dunes, has many car-sized boulders in it. Some are surrounded by ditches in the sand, like little moats. Why? The sand is blown […]