Early in the morning on Friday, October 9, 2009, NASA's Lunar CRaterObservation and Sensing Satellite (LCROSS) will be deliberately crashedinto a permanently-shadowed crater near the Moon's south pole, as part ofan experiment to detect the presence of water on the Moon.
(See for details on the mission.) The Atlas Centaursecond stage will be impacting at 4:32 AM in the morning on Friday, andshould throw a huge plume of ejected material into the lunar sky, where itcan be observed and analyzed. The plume should be visible from Earth withthe use of a good telescope in an area with clear skies.
Rick