Comment Re:Water sublimating (Score 4, Informative) 364
Indeed it does, and it's probably better explained using a triple point diagram:
http://www.chemistrydaily.com/chemistry/Image:Phase-diag.png
On earth (at higher pressures), increasing temperature goes from the solid, to liquid, and then to gas phases (the triple-point in the middle is at zero degress celcius)
The lower atmospheric pressure on Mars (~1% of sea-level earth pressure) means that you go straight from solid to gas. In fact, the liquid part is actually impossible (IANAChemist) unless you increase the pressure sufficiently.