We have known for several years now that there is ice in craters located at the north and south poles of the Moon. But what has been elusive is trying to figure out out how much ice there is in these craters.
Scientists using the Lunar Reconnaissance Orbiter's (LRO) on board laser altimeter have been able to come up with a pretty good idea for the amount of ice in Shackleton Crater located at the south pole of the Moon. Because this crater is permanently in shadow - it never sees the rays of the Sun in its depths - scinetists illuminated the interior of the crater with LRO's laser and were able to put together a pretty complete picture of the crater's interior.
The picture below shows the interior of the crater and the colors indicate the differeing elevations of the crater - orange highest and blue lowest. The team studying the crater was also able to measure the amount of laser light reflected off of the crater, its' albedo, and found it was very bright overall - an indicator of ice being present.
The results indicate as much as 22% of the surface material of the crater's florr and possibly walls could be made of ice. That is an incredible amount of ice when you consider the crater is 12-miles wide and two-miles deep!
Read More ABout It and see a GREAT video flyby of the crater http://science.nasa.gov/science-news/science-at-nasa/2012/20jun_shackleton/
Sky Guy in VA