The mysterious bright streaks

A Piece of Mars: Some things just go unexplained (so far, anyway). Here’s a mysterious bright streak (scene is 1.2×1.8 km, 0.75×1.12 mi) concentrated between two sets of ripple-like bedforms. It looks sort of like a river, but it’s on flat terrain and it’s not water. It’s part of a larger set of bright streaks

Dunes in a row

A Piece of Mars: Look at the alignment of the ~100 m dunes in this 713×750 m (0.44×0.47 mi) scene. How do dunes form in such straight lines? And why don’t they always do that? It’s likely that these dunes were once long ridges stretching from the lower right to upper left. The shape of

Ripples of rock

A Piece of Mars: To the upper right of this 0.85×0.6 km (0.53×0.37 mi) scene is a flat-lying plain strewn with large ripples. To the lower left is a rugged hill with gray rock laced with white veins (this might be part of an impact megabreccia identified nearby in Holden crater). Notice that some of


A Piece of Mars: There’s a fabric of erosion in this 1×1 km (0.62×0.62 mi) scene, with the main wind blowing from lower right to upper left (and if you look carefully you’ll see there’s a second, subtler fabric a bit clockwise from that one). The result is a landscape strewn with streamlined rock called

Black and tan

A Piece of Mars: Dunes in the top row in this 0.73×0.47 km (0.46×0.29 mi) scene are dark but those in the lower row are brighter. Why? They’re all probably made out of the same kind of sand, which is dark. And they all probably got covered by fine-grained airfall dust, which is bright. At

Mars’ corduory

A Piece of Mars: The wind on Mars likes to make textiles (unfortunately the term geotextiles is already taken for other purposes). This 1×0.6 km (0.62×0.37 mi) scene shows two different sets of ripples. The larger set has straight to wavy crests, and they’re ~18 m (~59 ft) apart, which is pretty big for ripples

Just do it

A Piece of Mars: It’s all about wind scour here in this 0.75×0.75 km (0.47×0.47 mi) view. The big “swoop” is an erosional channel dug into the surface by winds (blowing from the lower left) trying to erode the hills in the center. But notice that the hills are all aligned to the upper left/lower