User blog comment:WolfgangBSC/The Random Chat Room/@comment-24938973-20151202183017/@comment-12161342-20151202222513

Martian poles won't be fully melting either. Earth has ice caps, and Mars will have them too. Sure, some water will come from melting polar ice, but the main sources will be comets(in fact, I'm very close to starting a major bombardment) and martian permafrost.