In space it often isn&#x27;t so much boiling (liquid+heat=gas) as sublimation (solid+energy=gas).  Sublimation can, weirdly, occur well below the freezing&#x2F;boiling point.  That one lone cosmic ray can heat a single molecule of water enough to cast it into space as a gas ... all in an environment where the average temp is well below freezing points.  Temperatures in vacuum are strange.