Tag Archives: dunes

Springtime for sand dunes and polar ice

A Piece of Mars: This 480x270 m (0.3x0.17 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 ...

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 = 84ยบ, Mars Year 33 (about 12 sols from northern summer and southern winter solstice on Mars). It is sol 1200 of ...

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 excited now ...

Very long ripples

A Piece of Mars: Most of the scene (0.96x0.54 km or 0.6x0.34 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 ...

Peas in a pod

A Piece of Mars: These "peas-in-a-pod" are dunes covered in long ripples (the scene is 960x480 m, or 0.6x0.3 mi). They're a bit odd, surrounded by a rippled apron. It reminds me of melted-looking dunes that are common in ...

Dune trails

A Piece of Mars: The dark dunes in this 0.96x0.54 km (0.60x0.34 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. ...

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 ...

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 ...

Frosty dunes

A piece of Mars: In this image (0.96x0.54 km or 0.6x0.33 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 ...

Small dunes on Mars

A piece of Mars: These dunes are some of the smallest on Mars. The smallest in this frame is ~150 m long (492 ft). But the smallest Earth dunes are ~20 m across. Why are they so much bigger on ...