LCROSS spacecraft discovers water on the Moon
Scientists chose a crash site inside a crater in permanent shadow, in the hope that any water contained within will not have been evaporated over time by the heat of the Sun.
The LCROSS impactor was launched alongside the Lunar Reconnaissance Orbiter (LRO) back in June 2009, and was made up of two components that seperated shortly before impact; the Atlas V Centaur upper stage rocket (i.e. part of the launch vehicle) and the LCROSS spacecraft with its array of sensors.
The impact of the Centaur rocket created a debris plume that rose above the crater walls, and was then visible to the following LCROSS craft. During the four minutes before LCROSS itself crashed, it was able to take many images and measurements. The data that was transmitted back to Earth appears to show plenty of evidence that water was indeed present in the debris plume.
The existence of water on the Moon is an important discovery, because scientists hope to build a lunar base in the future. This task will be made alot easier if we don't need to transport water to the Moon by spacecraft, but can extract it from below the surface.
If you would like to know more about the LCROSS mission, then please visit the LCROSS website.