They discovered cosmic events found in asteroids and comets such as iridium and platinum. Using radiocarbon and typological dating, researchers estimate that the cosmic event occurred between 252 and 383 CE. The finding coincides with 69 near-Earth comets, which were observed and documented by Chinese astronomers as well as witnessed by Native American peoples.
"What's fascinating is that many different tribes have similar stories of the event. The Miami tell of a horned serpent that flew across the sky and dropped rocks onto the land before plummeting into the river. When you see a comet going through the air, it would look like a large snake," said Kenneth Tankersley, a professor of anthropology at the University of Cincinnati, who is Native American.
"The Shawnee refer to a 'sky panther' that had the power to tear down a forest. The Ottawa talk of a day when the sun fell from the sky. And when a comet hits the thermosphere, it would have exploded like a nuclear bomb," he added.
Researchers believe the comet airburst affected a huge area, bigger than the state of New Jersey, causing fires across 9,200 square miles. It could have resulted in the burning of forests, agricultural fields and buildings and possibly in the deaths of people.
"People didn't have good ways to store corn for a long period of time. Losing a crop or two would have caused widespread suffering," says study author David Lentz, a biologist at the University of Cincinnati.