Dune trails

There’s so much going on in this 0.75×0.75 km (0.47×0.47 mi) image. You’re looking at a broad dune migrating toward the upper right. It’s early summer, but this is close enough to the north pole that some winter ice lingers (pale blueish white), amid slumps that have shed down from the dune. The slumps probably

Ius Chasma dunes: they move

Many dunes on Mars are actively migrating, like these dunes (view is 0.4×0.5 km, 0.25×0.31 mi). These are found deep in Ius Chasma, one of the Valles Marineris. These dunes slowly migrate toward the right, pushed by winds blowing from the lower and upper left. Comparing this recent image with the first HiRISE image taken

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

Smash! Whoosh…

A Piece of Mars: The dark splash pattern in this 0.9×0.9 km (0.56×0.56 mi) scene (click on it for a better view) is the site of an impact crater that appeared between images sometime between August 2006 and March 2010 (Smash!). The main crater is ~7 m (23 ft) across. Impacts smash a little ways

Dunes with comet tails

A Piece of Mars: The north polar dunes in this 575×325 m (0.36×0.2 mi) scene are made of dark sand covered by bright winter frost (which will soon sublimate away, as this image was taken in late spring). To the right of the dunes extend pale yellow bumpy hills, making the dunes look like they

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