BOB HIRSHON (host):
The birth of a killer asteroid. I’m Bob Hirshon and this is Science Update.
65 million years ago, a six-mile-wide asteroid slammed into the Earth. This may have spelled doom for the dinosaurs. Now, a team of scientists has figured out where the killer asteroid may have come from. Planetary scientist William Bottke of the Southwest Research Institute in Boulder, Colorado, says it was probably a fragment of a much larger asteroid called Baptistina – about 100 miles across – that had been shattered by a collision in outer space.
WILLIAM BOTTKE (Southwest Research Institute):
This breakup happened very close, almost right on top of, for lack of a better way to put it, a dynamical superhighway: an escape route out of the asteroid belt.
— allowing some of the pieces to eventually cross Earth’s path. The evidence comes from computer models, combined with chemical signatures that match the impact on Earth to Baptistina. I’m Bob Hirshon, for AAAS, the science society.