spacetoday.net: Scientists find evidence of ancient giant crater

Posted: Fri, May 14, 2004, 7:41 PM ET (2341 GMT)
Asteroid impact illustration (Don Davis/NASA)

Scientists announced Thursday that they have found evidence of a giant crater buried off the coast of Australia that may be linked to the extinction of most life forms on Earth 250 million years ago. In a paper published this week on the web site of the journal Science, scientists said that they believe that Bedout, a structure 200 kilometers across off the northwest coast of Australia, is the remnant of a crater created 250 million years ago when an asteroid or comet struck the Earth. That impact is linked to the "Great Dying" at the end of the Permian, an extinction event that killed off 80 percent of life on land and 90 percent of marine life. Meteoritic fragments found in Antarctica and shocked quartz located there and in Australia also support this hypothesis, scientists said. Other scientists caution, however, that those rocks could be created by events other than impacts, such as volcanic eruptions.