As I write this, there is a NASA spacecraft on an unstoppable collision course with the moon.

Early on Friday morning it will impact a crater near the moon’s south pole at 9000 km/hr, causing an explosion that will excavate 350 tons of lunar rocks, blasting them up into space and leaving a 66 foot-wide crater.

Of course, this is all intentional. The LCROSS mission will use the upper stage of the rocket that launched the Lunar Reconnaissance Orbiter to the moon as a missile to blast the possibly ice-bearing crater Cabeus in much the same way that the Deep Impact mission blasted a hole in comet 9P/Temple. The hope is that the ejecta from the LCROSS impact will reveal that the crater does indeed contain ice.

In addition to the “shepherd” spacecraft that will follow the big Centaur stage to its explosive death, snapping pictures all the while, scientists all over the world will be watching the moon with their own telescopes. In fact, even large (12 in or 30 cm) amateur telescopes may be able to see the impact!

Even if you don’t have a big telescope to peer through, NASA TV will be covering the impact. The impact is planned to occur on Oct 9, 2009 at 11:31:30 UTC (04:31:30 am PDT), and NASA TV coverage will begin at 10:15 UTC (03:15 am PDT).

Stay tuned! It promises to be a blast! (Sorry, the pun had to be made.)