Deep Impact

Chicago Tribune

The climax of the Deep Impact mission, tracked by the probe's mother ship as well as the Hubble and other telescopes, could provide the most riveting holiday gift from NASA since Apollo 8's first manned orbit of the moon on Christmas Eve of 1968.

Deep Impact is an elegant experiment, if "elegant" can be applied to a kamikaze attack on a dirty space snowball half the size of Manhattan.

The ancients considered comets harbingers of doom, but modern scientists think they are refuse from the birth of the solar system.

Many comets may have smacked into Earth in its infancy, seeding it with the raw building blocks that eventually came together to create life.

The surfaces of comets have baked in the sun for eons, but trapped inside is pristine stuff that could help tell us how we came to be. ...