On Friday, October 9, two space ships will crash into the moon, and you will be able to see it happen.

All you need to do is find the crater Cabeus, which is near the Moon's south pole. Be watching at 11:30 UT (That's 4:30 a.m. Pacific Time, 6:30 a.m. Central.) Bring your telescope. It should be a pretty good telescope. According to NASA:

"We expect the debris plumes to be visible through mid-sized backyard telescopes 10 inches and larger," says Brian Day of NASA/Ames. Day is an amateur astronomer and the Education and Public Outreach Lead for LCROSS. "The initial explosions will probably be hidden behind crater walls, but the plumes will rise high enough above the crater's rim to be seen from Earth."

If you live in the eastern part of the United States or anywhere towards daylight (east) from there, it may be too bright. Hawaii is ideal within the US, but anywhere west of the Mississippi is a potential viewing spot. I live four blocks east of the Mississippi, so I guess I'll have to drag my telescope down to the shore and canoe across for better viewing!

There is another way to see the impacts: Tune in NASA TV. Coverage starts at 3:15 a.m. PDT. In some areas, you may get that station on your local cable system.

But why are the spaceships crashing into the Moon? Has something gone terribly wrong? Are we being invaded by aliens?

Well, this is an experiment cooked up by NASA to see if there is water on the Moon. First, a rocket called The Centaur will hit the moon. This rocket weighs about 2,200 kg and it is going fast, so there will be a great deal of energy released. A huge plume of debris will be blown up as much as 10 kilometers. This plume will be observed from earth, the Hubble space telescope, and the Lunar Reconnaissance Orbiter (LRO), and analyzed for presence of water.

However, close behind The Centaur will be the LCROSS space ship. This craft has instrumentation on it that will allow a much more detailed analysis of the plume. LCROSS will fly into the plume sent up by The Centaur, analyze the material really fast, and send its data back to earth. And then ... it will also crash into the moon.

"If there's water there, or anything else interesting, we'll find it," says Tony Colaprete of NASA Ames, the mission's principal investigator.

LCROSS will hit the moon about four minutes after The Centaur. The most interesting statement in NASA's press release regarding this experiment is probably this one:

"Remember, we've never done this before. We're not 100% sure what will happen, and big surprises are possible."

If you are interested in viewing this spectacular lunar experiment at a public event (and the public events are quite diverse as to what they offer, see if there is one in your area and refer to the LCROSS Viewer's Guide.