Almost Blue

A sea of dark dunes, sculpted by the wind into long lines, surrounds Mars’ northern polar cap and covers an area 19 miles (30 kilometers) wide. Credit: NASA/JPL-Caltech/ASU.

Dunes

The above picture, captured by NASA’s Mars Reconnaissance Orbiter’s HiRISE (High Resolution Imaging Science Experiment) camera on February 17, 2021 at local Mars time of 14:15, shows a field of sand dunes stretching out over a frosty 5-kilometer diameter crater in the high-latitudes of the northern plains of Mars. Credit: NASA/JPL-Caltech/University of Arizona.