The Deep Impact space probe has released its "impactor", which is now zooming towards the comet Tempel 1 at a speed of 23,000 miles per hour. It's scheduled to hit at 1:52AM EDT -- that's 10:52PM tonight for those of us on the west coast of the US, or just about 9 hours from the time of this posting.

The impact should be visible with a moderate telescope. But if you don't have a scope, have too much surrounding light to catch an image, or simply live on the wrong side of the planet to see it, NASA is providing a "Near Real-Time" image viewer.