Caption Spotlight (14 May 2019): A Frosted Surface

This is the first of a new monitoring series to track seasonal processes. It is also a striking image with late winter angled illumination over dunes covered by carbon dioxide frost mixed with dust.

Dark spots may be where sand is exposed from very early defrosting activity. The incidence angle is 87 degrees, or just 3 degrees above the horizon.

NASA/JPL/University of Arizona