It’s a disaster scenario that Hollywood has picked up on (think Deep Impact). An incoming object menaces the Earth. Scientists try to destroy it with nuclear weapons, but the horrified populace soon discovers that the blast has simply broken the object into pieces, each with the potential to wreak havoc planet-wide. Now we learn that an impact between two asteroids causing a similar crack-up may have resulted in the cataclysmic event some 65 million years ago that destroyed the dinosaurs. Researchers from Southwest Research Institute and Charles University (Prague) have been studying the asteroid (298) Baptistina, combining their observations with...