Huge Comet That Crashed in Nevada May Have Triggered Mass Extinction

New evidence supports a theory that a comet slammed into southern Nevada 370 million years ago and may have been the first of a series of strikes that triggered a mass extinction of many forms of life. A team of researchers told a Geological Society of America meeting in Salt Lake City that the comet hit roughly 130 miles northwest of Las Vegas when the region was covered by ocean.

The comet was two-thirds of a mile wide and blasted a 120-mile-wide crater in the sea floor, ripping apart a reef on what was then the continental shelf and creating 1,000-foot-high waves that carried pieces of reef as much as half a mile wide over much of southern Nevada. The crash happened 3 million years before one of the five greatest extinctions of life in Earth’s history occurred, at the end of the Devonian Period, when most organisms lived in the ocean.