Chemists at the University of Chicago have discovered yet another piece of evidence to support the theory that an asteroid struck the Earth 65 million years ago, touching off a worldwide conflagration that wiped out the dinosaurs. The evidence, found by Wendy Wolbach, Roy Lewis and Edward Anders and reported in the journal Science, is a global layer of soot in sediments from the end of the Cretaceous period, just when the dinosaurs vanished. The likely cause of these continent-sized fires was the impact of a large meteorite or asteroid, they concluded.
The research bears both on the question of the extinction of the dinosaurs and on current work on nuclear winter, which is believed to be a consequence of nuclear war. "Our data suggest that some of the assumptions used in nuclear winter scenarios were too optimistic," the Chicago scientists wrote. "Soot production by large wildfires appears to be 10 times more efficient than assumed. Thus cooling of the Earth would be more pervasive and long lasting than has been thought."