The dinosaurs’ fate may have been sealed by a piece of shrapnel from a cosmic collision that occurred long before the asteroid smashed into the Yucatán Peninsula 65 million years ago. Poring through a database of objects in the asteroid belt between Mars and Jupiter, scientists at the Southwest Research Institute in Boulder, Colorado, found debris from an ancient collision. In a chaotic cluster of asteroid shards, scientists glimpsed a void—evidence that part of the cluster had moved toward the inner planets, possibly sending the killer asteroid to Earth.
Asteroids are a lot like pinballs in the machine that is the solar system, says William Bottke of the SwRI team. “You shoot a ball and it goes all over the place, but if you shot a million balls and tracked where they went to the bottom, eventually you’d come up with trends.
Bottke and his colleagues were able to find ...
