January 13, 2014

Mars’ fleets of rock “boats”

A piece of Mars: Where the wind blows strong and there’s a lot of sand, the surface gets scoured. Some bits of the ground, called yardangs, are more resistant and stick around: they take on shapes elongated in the direction […]
November 29, 2013

Two-toned washboard on a hillside

A Piece of Mars: Two-toned ripples have formed on a steep slope, created by winds rushing downhill (from top to bottom in this frame). The larger ones are big ripples, with peaks more than 30 meters apart. What makes them […]
November 25, 2013

Cloaked rocks

A Piece of Mars: These rocks look like hooded figures from some dark fantasy story. European standing stones should be jealous, they don’t typically get a shroud of dark sand to add to their mystery and etch them into beguiling […]
November 13, 2013

Boulders on high

A piece of Mars: Right at the edge of the largest volcano on Mars (Olympus Mons) is a steep cliff. Here, near that edge, are some car-sized boulders poking out from a thick blanket of dust. Strong winds blow down […]
October 11, 2013

Relentless wind

A piece of Mars: This is what the relentless work of the wind can do. That vaguely circular structure in the center of the image is probably the remains of a ~150 m diameter impact crater. Since it formed, it’s […]
August 29, 2013

What the wind brings, the wind takes away

A piece of Mars: These C and S-shaped things were once dunes that marched across the scene (from upper left to lower right), formed from sand deposited by the wind. Then that sand somehow became cemented, locking the dunes in […]
July 29, 2013

Screaming winds

A piece of Mars: This image is way up high on the Tharsis Montes on Mars, at an elevation of 5900 m (19,350 ft). At night the wind comes screaming down from some of the tallest mountains in the Solar […]
July 8, 2013

South polar dunes

A piece of Mars: The blue structures are rippled dunes found not far from the south polar cap of Mars. They are probably partially active, enough to create the fine ripples found on and between the dunes. But the steeper […]
June 17, 2013

Hills, boulders, and wind

A piece of Mars: In the lower left of the image, a small hill stands above a plain partly covered by stabilized ripples. Boulders have rolled down the hill as it slowly erodes. If these ripples aren’t ever activated by […]