Impactor

NASA scientists say everything remains on course for what promises to be Monday's spectacular rendez-vous between the Deep Impact space probe and the comet, Tempel 1. The announcement follows the separation of the "impactor" from the fly-by space craft, which will record the massive collision.

cascade impactor

Chicxulub impactor

Although Dr. Bottke remains unconvinced that the impactor had a cometary origin, he noted that the asteroid explanation also raised many exciting and unresolved questions.