Tag Archives: yardangs

Erosional remnants

A Piece of Mars: The erosionally-streamlined bright areas are on high ground. They are remnants of a vast dusty mantle that once covered this whole area - the rest of it has been blown away. The surrounding regions (check out ...

Fossil dunes

A Piece of Mars: This 1.92x1.08 km (1.19x 0.67 mi) scene shows eroded ridges that are, in fact, lithified dunes. They are so old that you might not recognize them as dunes without more context. This doesn't happen much on ...

How to hide geology on Mars

A Piece of Mars: Three things are trying to hide in this 0.96x0.48 km (0.6x0.3 mi) scene. 1) Craters are slowly being both scoured and buried by migrating sand, 2) the sand itself is hiding in the lee of crater ...

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 ...

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 ...

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 ...

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 ...

Which wind came first?

A piece of Mars: This scene (3.9x2.5 km or 2.4x1.6 mi) shows a surface carved by two different winds: one blowing from the right and one blowing from the bottom right. They've formed overlapping sets of streamlined rocks called yardangs. ...

The always-changing landscape

A piece of Mars: Over time, windblown sand can wear down a surface. This isn't so common on Earth, where water, ice, and life are more likely to change the landscape, but it's typical of many places on Mars. Here, ...

Flow

A piece of Mars: This is a bit of the flank of Arsia Mons, one of Mars' great volcanoes. The big changes in topography are ancient relics of erosion by lava and great tectonic pulling. What I like is that ...