Dredd,I must admit, I have no knowledge whatsoever concerning all that interstellar stuff, although I was a minor fan of the early Pink Floyd stuff - LOL! Me thinks peak oil and other terrestrial energy concerns are going to put a damper on any US efforts to expand our reach into space. I actually think we've already passed peak everything in terms of currently defined abundance. Debt and resource depletion already have us in a vice grip, we're just not yet prepared to fully acknowledge it. The wars are merely a symptom, and there'll be plenty more to come. The fun is only beginning, and for those fortunate to stay out of harm's way, the carnage is going to be spectacular!
disaffected,There is a theory set forth by an astronomer who headed the U.S. Naval Observatory for some years, which this mystery fits into.The theory is that this solar system contained another planet that was located between Mars and Jupiter.It was destroyed somehow.Its remains are the asteroid belt and some moons orbiting Mars, Jupiter, and Saturn.It is what caused the cratering on planets and moons in this solar system.This water-ice on that asteroid would fit that theory, since the planet that was destroyed was a water world like the Earth, and like Mars and Venus once were too.Here is a link to one post about it.