In late fall, when the temperatures are falling, carbon dioxide in the Martian atmosphere condenses into ice and settles on the Martian surface. With spring and summer warmth, the frost will vaporize again to rejoin Mars' atmosphere.
January 26, 2013 9:00 AM PST
Photo by: NASA/JPL-Caltech/Univ. of Arizona
| Caption by: James Martin
Conversation powered by Livefyre