Reusing old canvases

The wind on Mars is an artist, or at least it tries really hard to be one. It flutters up and down mountains, winding along valleys, dragging its wings in the sand and building up really amazing structures that could win any sand sculpture award. Well okay maybe I’m a little biased. Like this 0.92×1.325

Flow. Lots of flow.

Over the years, many things have flowed across the surface of Mars: lava, ice, water, and wind. Two things have flowed in this image (the view is 0.75×0.6 km or 0.47×0.37 mi): Image credit: HiRISE ESP_026541_1840, NASA/JPL/Univ. of Arizona If you know my blog at all, then you might recognize the big structures as yardangs.

Where dune fields begin

This is the upwind edge of a dune field (825×625 m, 0.51×0.39 mi). Winds blow down a cliff (offscreen) from the lower right, blowing sand toward the upper left. Elongated dunes have formed parallel to the resultant wind direction, only avalanching into slip faces once enough sand has piled up (there are two slip faces

Arnus Vallis, Mars

A Piece of Mars: This is a section of Arnus Vallis (scene is 1.25×1 km, 0.78×0.62 mi). It’s a >300 km long valley that was carved out, not by water, but by lava, long ago. Since then the wind has taken over. The left wall of the valley seems to have layers etched into high

Fuzzy dunes

A Piece of Mars: The dunes (or maybe they’re ripples) in this valley appear to be fuzzy (the view is 625×775 m, 0.39×0.48 mi). They’re not really fuzzy, but it’s not actually clear what’s going on. They seem to have smaller ripples superposed on them, and maybe bright dust has settled into the troughs between

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

Island in the stream

A Piece of Mars: In the floor of what might have been an old fluvial channel there are a bunch of really neat dunes (or maybe ripples, they’re TARs and we don’t know yet what they are). One spire pokes up here, ~200 m (656 ft) across and ~90 m (295 ft) tall. The TARs

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