Water on the moon comes from the solar wind

The discovery of water in the soil of the moon is recent but a few years old (here's one post from 2009 on it), and though the sun was thought to be the likely source it was a bit speculative. A new study has concluded that the sun should be the source, due to the lack of deuterium - read about it here. Why this is important is a no-brainer:

"With the cost of $25,000 for taking one pint [half a liter] of water to the moon, it is essential that we develop processes of producing water from the materials on the moon," study co-author Larry Taylor, a planetary geochemist also at the University of Tennessee, said in a statement.

Perhaps just as important as the cost of water is the fact that this process should be that which creates water on a great number of other bodies in the Solar System and beyond, and the moon is the easiest place to investigate to understand it. Doing so will aid in predicting surface conditions of bodies even in other solar systems, so the more we know about our own the better.