HiRISE images

A piece of Mars: Patterns within patterns (metapatterns?).  These small martian dunes shown an unusual complexity in their crossing lines, indicating that they were formed by winds from several directions (and it is likely that those winds changed over time). What do you think, should it be the next thing in tweed fashion after houndstooth and herringbone? read more ❯

A piece of Mars: It's high summer in the northern hemisphere of Mars. Here, dark dunes near the north pole have finally lost the seasonal ice that blankets them and turns them white for most of the year. For a brief time we can see the true contrast between the dark dunes and the bright terrain they are slowly crawling over. (HiRISE ESP_026598_2650) read more ❯

A piece of Mars: Here are some lovely ripples on Mars. In the same field of ripples, there are large wavy white ones and small complex blue ones. Why are there two different types, made distinct by their color, size, and shape? Nobody knows, but it's a good bet the sand grains that they're made of have different sizes and composition. Regardless of why they look the way they do, they're still quite pretty. (HiRISE ESP_026388_2300) read more ❯

                    A piece of Mars: Today's image comes courtesy of my postdoc, Simone Silvestro. He's studying migrating dunes and has made a 3 image movie of a dune moving across the surface of Mars. This one crawls at a rate of ~0.5 m/year, and it isn't far from where the Curiosity rover will pass when it lands later this year. read more ❯

A piece of Mars: Mottled dunes hint at different wind gusts, in this field of dunes located near the landing site for the next rover to go to Mars (named Curiosity). The bluish areas are most likely the more recently active patches -- think of wind gusts suddenly causing sand to hop along the ground, scouring off dust (like a brillo pad) and revealing the true colors of the dunes. The small scratches on the dunes (the ones that make the dunes look like troll doll hair) are actually sand ripples, and they have been observed to move over time.... read more ❯

A piece of Mars: Of Sandy Lanes. The yellowish-tan rocks are tall high-standing hills that have been scoured by the wind. Dark sand slowly cuts down the whiter rocks in the valleys, slowly creating majestic lanes bordered by steep, sharp hills. My guess is the sand is moving from top to bottom in this image. (HiRISE ESP_023051_1865) read more ❯

These dunes are quite unusual for Mars, and difficult to interpret. The thick blue and white stripes are dunes in their current location, but subtle stripes above them seem to indicate former positions of dunes, small pieces that got left behind as the dunes marched toward the bottom of the image. (HiRISE ESP_022645_1505) read more ❯