Actually, I think it might have been Helium-3. But what is a noble gas doing on the surface of the moon?

It was rockets all the way.


EDIT: Looking at Wikipedia, I'm questioning the accuracy of those calculations. Turns out that one researcher claimed that only 3 missions a year would be necessary to supply energy to the entire world, but a more accurate value would be closer to one a week. I just don't know which set of calculations the guy who told me about it was referring to.

As I said, it is in the solar wind, which the moon is exposed to. The sun generates quite a lot of Helium.

I get that much. How does it stay on the moon, given that it has no atmosphere?