dunes

January 12, 2016

Springtime for sand dunes and polar ice

A Piece of Mars: This 480×270 m (0.3×0.17 mi) scene shows a dark dune peeking out from under its cover of winter frost. In this picture it’s late spring, but still cold up at this latitude – it’s as far […]
December 21, 2015

Curiosity about sand dunes (part 2/2)

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 […]
December 14, 2015

Curiosity about sand dunes (part 1/2)

Sorry for the pun in the title there, but NASA asked for it by naming their rover like that. And you’ve seen it done a hundred times, so let’s grit our teeth, smile, and carry on. Anyway. So I’m more […]
November 4, 2015

Very long ripples

A Piece of Mars: Most of the scene (0.96×0.54 km or 0.6×0.34 mi) is one long slope of a dune. The crest is the line in the top right; the ground below is in the bottom left. If you ever […]
October 19, 2015

Peas in a pod

A Piece of Mars: These “peas-in-a-pod” are dunes covered in long ripples (the scene is 960×480 m, or 0.6×0.3 mi). They’re a bit odd, surrounded by a rippled apron. It reminds me of melted-looking dunes that are common in high […]
October 5, 2015

Dune trails

A Piece of Mars: The dark dunes in this 0.96×0.54 km (0.60×0.34 mi) scene are slowly migrating towards the lower left. Look closer and you’ll see brighter ripples between the dunes – the biggest ones are ~8m (26 ft) apart. […]
August 26, 2015

Stealth bomber dunes

A piece of Mars: These dunes look strangely triangular, a little bit like a flock of stealth bombers. Why? They’re two-faced barchans. Each flat face is an avalanche slope that faces downwind, formed by one of two distinct wind patterns […]
July 27, 2015

Dust devils and wind scours on ripples on dunes

A piece of Mars: So much wind. There are dark swirly tracks of dust devils that have passed by, ripples covering dunes, wind scours around rocks, and of course dunes. Dune crests have a different color than other regions: are […]
July 6, 2015

Frosty dunes

A piece of Mars: In this image (0.96×0.54 km or 0.6×0.33 mi), it’s late winter and the sun is barely above the horizon here near the north pole. The dunes are covered in winter frost, most of which is CO2 […]