What is on the floor of the permanently shadowed craters at the moon's poles? What do the the hydrogen signatures in these craters mean? LCROSS is looking to answer these questions.
Water could only exist in areas of permanent shadow and those areas exist at the lunar poles.
The resulting Centaur impact crater will be approximately 28m (92 feet) in diameter by 5m (16 feet) deep
Five days after launch, flight engineers execute a maneuver that takes the LCROSS spacecraft and the Centaur on a large looping orbit around the Earth/moon system.
Clementine (Deep Space Program Science Experiment, DSPSE) gave scientists their first total look at the the Moon's landscape. The spacecraft also found signs of a large deposit of ice in a permanently shadowed crater on the Moon's south pole.
In March 1998, mission scientists announced tentative findings of the presence of water ice in shadowed craters near the Moon's south and north poles, based on reasonable scientific assumptions from the levels of hydrogen detected, from which water ice is inferred. They estimated that up to six billion metric tons of water ice may be buried in these craters under about 18 inches of soil.