aeolian
December 27, 2013
A piece of Mars: A single dune sits on the surface of Mars, not too far from the north pole. It’s early spring, but this far north the dune is still covered in white CO2 frost (as well as a […]
December 23, 2013
A piece of Mars: Normally I post color images, but this one is just too cool to skip. These ripples formed ages ago: long enough ago that the impact of several small bolides formed craters (seen on the left), disrupting […]
November 29, 2013
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
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
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 25, 2013
A piece of Mars: Barchan, or crescent dunes, are generally thought to form from winds blowing from a single direction. Reality isn’t usually that nice. Here are two barchans with crescent-shaped slip faces on their eastern (right) sides, indicating that […]
October 11, 2013
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 […]
September 4, 2013
A piece of Mars: In the center are two dark dunes, racing one another to jump over hurdles formed of older, now inactive dunes (or maybe those bright things are ripples, we still don’t know for sure). The dune in […]
August 29, 2013
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 […]
August 8, 2013
A piece of Mars: Creamy dunes (or maybe they’re very large ripples) wind their way northward between mesas. More recently darker, more mobile sand (bluish here) has piled up against the western slopes of the mesas. We don’t know why […]
July 8, 2013
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 […]
July 3, 2013
A piece of Mars: Topography makes for great landscapes. It also funnels winds, forcing dunes and ripples along particular pathways. Here a cliff (high ground is yellow) has forced low-lying, dark ripples to migrate up a slope at the end […]