NASA's Lunar CRater Observation and Sensing Satellite (LCROSS) satellite, which was sent to the moon last summer and crashed into it in early October, has revealed some interesting data -- water!
This image shows the spectrometer's field of view (the red circle) focusing on the plume of dust about 20 seconds after impact. (A spectrometer examines what light or near-visible radiation -- infrared and ultraviolet -- is absorbed or emitted to determine the composition of a material.)
The red line in this image has been altered within the yellow bands to show what the readings would be if water were present in the plume. This is the evidence NASA was looking for: There is water on the moon!