Tag Archives: erosion

Light and dark

A Piece of Mars: This 0.96x0.54 km (0.6x0.34 mi) late winter scene is a study in contrast. The dark top half is uniformly rippled. This is the shady surface of the main windward side of one of Mars' biggest dunes, ...

Eroded dune

A Piece of Mars: Barchan dunes on Mars have a characteristic crescent shape, with a steep slope ("slip face") on the inside of the sharpest curve (see examples like this, this, these, or this). This image (873x491 m, or 0.54x0.31 ...

Where does the windblown stuff come from?

A Piece of Mars: How far do windblown materials move on Mars? This scene (0.9x1.2 km, 0.56x0.75 mi) shows a bright layer of bedrock (top right) that is eroding, exposing a darker, bluish rock (bottom left). Ripples 5-20 m wide ...

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 ...

Ancient ripples?

A Piece of Mars: Potential signs of wind activity are everywhere on Mars. Take this 0.96x0.54 km (0.6x0.34 mi) scene, which is on bedrock dated to be several billion years old. There's a fabric of ridges trending from the upper ...

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 ...

When the martian surface is eroded, pretty things emerge

A Piece of Mars: Just like at Earth's Grand Canyon, erosion on Mars has created some really beautiful landscapes. This 480x270 m (0.3x0.17 mi) scene shows rugged terrain that was once buried in sediment. Does the texture here represent the ...

Where we have been

A Piece of Mars: This 0.98x0.54 km (0.61x0.34 mi) scene shows ancient windblown bedforms (maybe dunes) that have been partially eroded by the wind. The wind has left behind ghostly stripes: these are remnants of where these things once were, ...

Dune cannibals II

A Piece of Mars: This 0.96x0.54 km (0.60x0.34 mi) scene shows two sets of bedforms (dunes), each aligned in different directions. The more closely-spaced set has sharper crests, and it's superposed on top of (and it is therefore younger than) ...

Wind shadow

A Piece of Mars: There's a dune field migrating past a 230 m (755 ft) diameter crater, creating a 1.6 km (1 mi) long "shadow" that's empty of dunes. Why? The rim of the crater pokes up just enough to ...