"We and all living creatures are living dangerously on the earth," Tickell said in a speech titled "Impacts from Space: Past, Present, and Future." "Only the shortness of our lives shields us from how vulnerable the earth is."
Tickell warned that the risk of being killed by an asteroid is only slightly lower than that of dying in a plane crash. And while the comparison may have gained resonance since September 11, Tickell admitted that the possibility remains extremely remote. Still, he called for a coordinated international effort to study the extent of the threat and ways to prevent major impacts. To fail to do so, he said, would be greatly irresponsible (not to mention that it would leave the human race vulnerable to the same fate that befell the dinosaurs). Tickell said he hopes it doesn't take a tragedy to focus attention on the destructive potential of extraterrestrial objects. But even disasters sometimes have benevolent effects.
"You don't want your catastrophe to be too big or too small, too fast or too slow or to affect anyone in this room," he said. "But catastrophes can help produce change.