Buzz Aldrin on Star Talk

Buzz Aldrin joins the lively crew of StarTalk Live.

http://www.podtrac.com/pts/redirect.mp3/media.startalkradio.net/uploads/shows/STR-S04E28-2013-09-22-startalk-live-at-town-hall-with-buzz-aldrin-part-2.mp3

Can Liquid Water Exist on Mars?

I wondered whether water was possible on Mars due to the atmospheric pressure differences from Earth. I wondered whether the pressure differences would cause the freezing point to shift to a lower temperature because of the lower pressure. Apparently, only the boiling point is affected by atmospheric pressure, and the low pressure on Mars causes ice to sublimate directly into a gas (because the boiling point is below the freezing point), so there is no chance of liquid water being discovered on its surface.

WATER ICE Discussion - Mars Rover Blog and Forum