Researchers from the University of Cincinnati have found evidence of a cosmic cataclysm 1,500 years that may be responsible for the downfall of the Hopewell Culture. The Hopewell Culture was a widely dispersed set of pre-Columbian Native American populations connected by a common network of trade routes from 100 BC to AD 500 in the Middle Woodland period. The researchers found evidence of a cosmic airburst at 11 Hopewell archaeological sites in three states stretching across the Ohio River Valley in the United States, which rained debris down into the Earth’s atmosphere creating a fiery explosion around 1,500 years ago...