: A massive comet or fleet of comets struck or exploded over North America around 12,900 years ago, an occurrence the authors simply call "the Event".
: The authors connect scientific data to global oral traditions, suggesting that ancient legends of worldwide floods and "Thunderbirds" are actually eyewitness accounts of these cosmic impacts. The Cycle of Cosmic Catastrophes: How a Stone-A...
: Discoveries of radioactive mammoth bones and magnetic microspherules in specific sediment layers. : A massive comet or fleet of comets
: Puzzling elliptical depressions along the U.S. Atlantic coast that the authors link to the impact event. 900 years ago