[RightWhale]

early collisions between Earth and comets brought the vast amounts of water that now make up Earth's oceans.

This would be an expedient method to get some water to the moon so the moon can be made inhabitable. Not a small project, still it would be more powerful than using rockets to carry water from the earth to the moon.

[gomaaa]

Thought you were talking about teraforming the moon there for a second! Yeah, it would make it a lot cheaper to establish a permanent base if we didn't have to haul our own H2O up there. We could even use it to make rocket fuel there instead of shipping everything up from Earth, thus making a trip to Mars or wherever that much cheaper.

This all assumes we can figure out how to change the course of a comet. Not a small project, as you pointed out!