The Massive Ark on the Moon (very OT, but of high interest)

The Planetary Society Blog

LCROSS finds lots of water in accessible places at the Moon's south pole --but we'll have to tread carefully
Oct. 21, 2010
http://www.planetary.org/blog/article/00002728/

It is an "opportunity for the future": an intentional crash landing onto a permanently shadowed crater on the Moon has produced evidence of large deposits of water. And that's not all. The water is accompanied by other volatile materials like ammonia, formaldehyde, and mercury. It is most likely held within a "fluffy" lunar soil that would be easy for future explorers to dig into. And these deposits probably extend beyond the Moon's permanently shadowed spots into "permafrost" deposits in sunlit regions that would be much more benign environments for exploration by robots or humans than the cold, shadowed places. All in all, the Lunar CRater Observation and Sensing Satellite (LCROSS) has both achieved its goal of confirming the long-theorized presence of water at the lunar poles and revealed the polar regions to be enticing prospects for both human exploration and scientific discovery.

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This map shows that places on the Moon are very, very cold. 100 Kelvin would be cold enough to trap water for billions of years. But there's at least one spot that's only 29 Kelvin, which is the coldest place ever directly measured in the solar system. (Such temperatures are theorized to exist in places like the Kuiper belt but have not actually been directly measured.) So water's not the only thing that's stable for billions of years; many other things are too, what Paige called "supervolatiles," stuff that's even more ready to vaporize than water. These materials include methanol, ammonia, sulfur dioxide, formaldehyde, carbon dioxide, and hydrogen sulfide. If this list sounds familiar, that's because they are the sort of simple hydrogen, oxygen, sulfur, nitrogen, and carbon compounds that form the "building blocks" of two important things: all the cold stuff in the solar system (like comets, the polar caps of terrestrial planets, the surfaces and interior oceans of icy worlds) and, of course, the chemistry for life on Earth. The idea that this stuff is present at the poles of the Moon, until relatively recently thought of a baked-dry world, is pretty exciting.