December 27, 2013

Wintery dune

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

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 […]
December 11, 2013

The holes get filled in

A piece of Mars: Sand that moves into holes in the ground tends to get stuck there. That’s why this round hole ~150 m across, which was probably once a crater, is now brimming with sand and capped by ripples. […]