A Defrosting Mess

[Craig]

http://www.uahirise.org/ESP_029614_1105

 

This image is from the high latitudes in the Southern hemisphere, about half-way through southern spring.

Just like on the Earth, the frost layer that accumulates over the winter will disappear as summer approaches and Mars heats up. However, most of this frost is not made of water ice and snow -- on Mars, most of the frost/ice is made of carbon dioxide (also known as "dry ice").

This material will not melt, but instead will go directly from solid into vapor (a process called sublimation) as it heats up (above approximately 147 K, which is -195 F, or -126 C). In doing so, it'll create all sorts of interesting landforms.