It's a mystery scientists have been trying to uncover for years. How much water is there on the moon?

On Friday, NASA will get one step closer to answering that question when one of its rockets goes smashing into the lunar surface at a speed of 5580 miles per hour, penetrating 13 feet into the moon's surface.

The mission — called LCROSS — blast off last June. 

A satellite will photograph the debris plumes that result from the impact, which will help scientists detect water particles. Telescopes on earth will also record the impact.

[Anthony Colaprete, LCROSS Principal Investigator]:
"Having this diverse set of telescopes on the earth and in space and at the moon essentially makes us very robust and ensures our success, and definitely addresses the questions in a most diverse and expanded way as we possibly could."

The mission will cost an estimated 79 million dollars and can be observed live on NASA's website.