Tag Archives: dunes

Dunes carving up rock (3D)

A Piece of Mars: Get out your 3D blue/red glasses (or look here for a 2D version if you can't find them). This is a 3.2x1.8 km (2x1.13 mi) scene showing dark dunes carving lanes 50-70 m (165-230 ft) deep ...

Tortoise and hare

A Piece of Mars: There's a lot of evidence for both fast and slow movement in this 480x270 m (0.3x0.17 mi) scene. The tortoise: The rippled surface at the top is high ground: the top of a dune. Wind pushes ...

The trail of a dune

A Piece of Mars: A low, broad dune occupies the center of this 800x450 m (0.5x0.28 mi) scene, blown by a dominant wind towards the lower left. The slip face on the lee side has several small avalanches, formed as ...

Grainfall

A Piece of Mars: The dunes climbing over a rocky surface in this 0.96x0.54 km (0.6x0.34 mi) scene are mostly yellow because they're covered (and therefore kept immobile) by dust. The crest of one dune, though, shows recent activity: dark ...

Dunes and rock hurdles in Gale crater (3D)

A Piece of Mars: Wind from the upper left is blowing dark dunes toward the lower right in this 1.92x1.08 km (1.19x0.67 mi) anaglyph (if you don't have your red/blue 3D glasses handy, you can also check out the black ...

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 ...

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 ...

Dunes not in the global dune database

A Piece of Mars: Ten years ago I participated in a global survey of martian dunes. But we missed a few dune fields, like these beauties. They're small, low, and in rugged terrain, which made them difficult to spot in ...

Itty bitty changes: places where the wind barely moves sand

A Piece of Mars: Not all dunes on Mars are moving at a measurable pace. This 0.96x0.45 km (0.6x0.28 mi) scene looks a lot like one I posted 3 years ago called Martian Sports. This image shows the same dunes ...