Summary: NASA Readies Probe to Hit Comet

DEEP IMPACT: NASA's probe is set to hurtle into a speeding comet half the size of Manhattan and smash a hole in it. The goal is to view the icy core of a comet that may hold cosmic clues to how the sun and planets formed.

THE FIREWORKS: Scientists expect the collision to spray a cone-shaped plume of debris into space and leave a crater anywhere from the size of a house to a football stadium.

THE VIEW: Amateur astronomers in the western United States and Latin America should be able to view the impact through telescopes.