The LCROSS observations were made from the shepherding spacecraft, which followed
the Centaur rocket stage into the lunar south pole crater Cabeus. The Centaur
impacted the floor of Cabeus at a speed of 1.5 miles/sec sending out a cloud
of vapor and lifting a debris cloud more than six miles above the surface.
Instruments monitored the impact and made measurements of the vapor and dust
clouds. After approximately 3.5 minutes the shepherding spacecraft entered
the remnants the impact debris cloud and made the first observations of the
floor of Cabeus, including the still hot crater created by the impact of the
Centaur.
Video credit: NASA/Ames, Roger Arno