About a month from now on Friday morning October 9th at approximately 5:30 am MDT (11:30 UT) the Lunar Crater Observation and Sensing Satellite (LCROSS) will crash into the western wall of lunar crater "Cabeus A" which is near the Moon's south pole. The satellite will be following an Atlas Centaur V upper stage rocket and fly into the plume of dust created from the impact of the rocket. LCROSS will measure properties of the dust plume to determine if any water ice was on the floor of the crater. It will then impact the lunar surface.
The project scientist and principal investigator,Tony Calaprete, said that the plume from the impact should be brightest somewhere between 10 to 60 seconds after impact. It is anticipated to be magnitude +5 in brightness and maybe as bright as magnitude +4. The plume should be for bright for about 30 seconds and then fade. See http://lcross.arc.nasa.gov/observation/amateur.htm for additional information.
Portion of image from 6:22 am Sept 11, 2009. Celestron Nexstar 11, F6.2 focal reducer, and Canon Xsi camera (ISO 200, 1/400 sec), aligned and stacked with Registax5.