The launch went off without a hitch yesterday, but what does “Deep Impact” do?

The idea behind Deep Impact is as simple as it is surprising: to find out the inner structure and make-up of a comet, what could be more natural than punching a hole in it? That is precisely what Deep Impact will do, by sending an impactor crashing into comet Tempel 1 at a speed of 10 kilometers (6 miles) per second – about ten times the speed of a rifle bullet.

It’s due to hit on July 4. I can’t wait.