NASA - National Aeronautics and Space Administration - Seasonal frost commonly forms at middle and high latitudes on Mars

Seasonal frost commonly forms at middle and high latitudes on Mars, much like winter snow on Earth. However, on the Red Planet most frost is carbon dioxide (dry ice) rather than water ice. This frost appears to cause surface activity, including flows in gullies. More:http://go.nasa.gov/1KCNzAV ‪#‎NASABeyond‬