NASA plans to crash a rocket into the moon early Friday, blasting a huge hole in the lunar surface to search for hidden water.
The explosion, scheduled for 4:30am Arizona time, is expected to visible with from Earth using any telescope, according to NASA.
It's also expected to be aired live by NASA-TV and on www.nasa.gov/ntv.
According to NASA's website, the Centaur rocket will make impact at the Moon's south pole.
Scientists tell Scientific American Magazine that they expect the blast to be so powerful that a huge plume of debris will be ejected.
A spacecraft will fly through the debris plume, sending data back to Earth before crashing into the lunar surface and creating a second debris plume, according to NASA's website.
Why blast a hole in the moon? NASA wants to see if any water, ice or vapor is revealed in the cloud of debris. If there is, that might provide supplies for a future manned moonbase.