Ebb and Flow (which were named in a contest by elementary school students) have been circling the Moon since January 1st, developing a detailed gravitational map of the Moon.

FORBES: NASA Prepares To Crash Its Probes Into The Moon

Scientists will then be able to use those measurements to produce a gravitational map of the Moon, just like GRACE did for the Earth.

FORBES: NASA's GRAIL Mission Will Unlock Secrets Of The Moon's Interior

The discovery of ice is sure to overshadow the many other things Lunar Prospector will achieve (such as the first complete map of the moon's gravity, also announced this week).

ECONOMIST: At least lunar gold-diggers will be able to take a shower