Tag Archives: stabilized

The millipede, rewritten

A piece of Mars: Looks like a millipede, doesn't it? It's something much larger and much less poisonous. It's an ancient dune (or maybe a ripple) on Mars, that once stretched ~285 m (935 ft) from lower left to middle ...

Ribbons on Mars

A piece of Mars: Bet you didn't know there were ribbons on Mars. Long, sweeping, velvety lines, delicately frayed at the ends. These are actually ancient ripples, formed by a wind blowing from right to left. Stripes on the ripples ...

Ancient and slightly less ancient

A piece of Mars: Here are two craters, each of which is ~240 m across. On the right is an old, very eroded crater. It has old, eroded ripples on its floor. The crater on the left is younger, with ...

Little dunes that Curiosity saw last October

A piece of Mars: On Oct. 15, 2013, Curiosity drove past a crater that has small dunes or ripples on its floor. In a new HiRISE image, you can see Curiosity's tracks from that day (its 424th sol on Mars). ...

Growth of ripples over time… a long time.

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 ...

Waiting for spring

A piece of Mars: These sharp-tipped hills are dunes near the north pole of Mars. At the height of summer they're lovely dark dunes, but because it's just barely spring here they're still covered in white frost (mostly CO2 ice, ...

Martian sports

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 ...

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 ...

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 ...

Polygons of dunes

A piece of Mars: Yep, these are dunes shaped into polygons. Each "cell" is about 25 m (~80 ft) across. The crests of these things are outlined in blue, as if somebody traced them with a pen (well it's stretched ...