A blast from heaven?

摘要

In 1989, Edward Bryant climbed a point on the southeast coast of his native Australia with a colleague and found an odd jumble of boul-ders well above the surf. A big wave, he thought, maybe a tsunami from an earthquake, must have tossed them up there. Over the next few years, however, the University of Wollongong geologist explored hundreds of miles of coast and found more signs of wave action, hundreds of feet above the water―too high for any quake-spawned surge. An astonishing hypothesis of devastation from outer space formed in his mind. It gathered some praise, along with many ferocious brickbats from doubting colleagues. But what may be a geologic smoking gun has now turned up in 1,000 feet of water just south of New Zealand. Columbia University geologist Dallas Abbott has found what appears to be an impact crater 13 miles across, implying that something enormous, maybe half a mile wide, smashed into the crust there.