slip face
March 5, 2018
Baby dunes on Mars are pretty big compared to those on Earth. In this 885×512 m (0.55×0.32 mi) frame, there are four dunes of roughly the same size, all of which are about as small as dunes can get on […]
June 5, 2017
A Piece of Mars: Having a bad day? You’re in good company with these dunes in this 0.96×0.48 km (0.6×0.3 mi) scene. The gray barchanoid dunes are covered in ripples, as the wind valiantly tries to push the sand to […]
April 10, 2017
A Piece of Mars: Sometimes I just want to show the interior of a dune field, because it’s full of waves: ripples and dune crests, slip faces, all of which signs of movement. The dunes in this 0.67×0.47 km (0.41×0.29 […]
March 27, 2017
A Piece of Mars: Sand pours in from the top of this 1.95×1.95 km (1.21×1.21 mi) scene. The sand piles up and up (here ~115 m or 377 ft high), but ahead (at the bottom) is a mountain poking up. […]
January 12, 2017
A Piece of Mars: There’s a lot of evidence for both fast and slow movement in this 480×270 m (0.3×0.17 mi) scene. The tortoise: The rippled surface at the top is high ground: the top of a dune. Wind pushes […]
December 19, 2016
A Piece of Mars: A low, broad dune occupies the center of this 800×450 m (0.5×0.28 mi) scene, blown by a dominant wind towards the lower left. The slip face on the lee side has several small avalanches, formed as […]
November 28, 2016
A Piece of Mars: The dunes climbing over a rocky surface in this 0.96×0.54 km (0.6×0.34 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 […]
September 19, 2016
A Piece of Mars: This 0.96×0.54 km (0.6×0.34 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, […]
December 21, 2015
Today is December 21, 2015 (northern winter and southern summer solstice on Earth). On Mars it is Ls = 84º, Mars Year 33 (about 12 sols from northern summer and southern winter solstice on Mars). It is sol 1200 of […]