DEBRIS thrown into space by the asteroid impact thought to have killed the dinosaurs 65 million years ago rained down so hot and heavy that for four days it ignited wildfires around the globe.
Geologists have found charcoal from the fires, but weren鈥檛 sure how they spread. Now a computer model produced by David Kring at the University of Arizona has shown the impact ejected trillions of tonnes of debris into space (Journal of Geophysical Research, DOI: 10.1029/2001JE001532). Most of it soon fell back to Earth, and the falling meteors heated the upper atmosphere and ground 鈥渟o significantly and for so long that even a humid rainforest would have been completely dried and ignited鈥�, says Kring.