Did A Comet Explosion Over North America Lead To Downfall Of Ancient Hopewell Culture?

Jan Bartek - AncientPages.com - The rapid decline of the Hopewell culture about 1,500 years ago might be explained by falling debris from a near-Earth comet that created a devastating explosion over North America, laying waste to forests and Native American villages alike.

Researchers with the University of Cincinnati found evidence of a cosmic airburst at 11 Hopewell archeological sites in three states stretching across the Ohio River Valley. This was home to the Ohio Hopewell, part of a notable Native American culture found across much of the American East.

Credit: Pixabay - Buddy_Nath - Public Domain

The comet's glancing pass rained debris down into the Earth's atmosphere, creating a fiery explosion. UC archeologists used radiocarbon and typological dating to determine the age of the event.

The airburst affected an area bigger than New Jersey, setting fires across 9,200 square miles between the years A.D. 252 and 383. This coincides with a period when 69 near-Earth comets were observed and documented by Chinese astronomers and witnessed by Native Americans as told through their oral histories.

The study was published in the Nature journal Scientific Reports.

UC archeologists found an unusually high concentration and diversity of meteorites at Hopewell sites compared to other time periods. The meteorite fragments were identified from the telltale concentrations of iridium and platinum they contained. They also found a charcoal layer that suggests the area was exposed to fire and extreme heat.

University of Cincinnati anthropology professor Kenneth Tankersley uses a magnet to show how micrometeorites collected at 11 Hopewell sites contain metals such as iron. UC's analysis found they also contain high levels of platinum and iridium. Credit: Michael Miller

In his lab, lead author Kenneth Tankersley, a professor of anthropology in UC's College of Arts and Sciences, held up a container of tiny micrometeorites collected at the sites. A variety of meteorites, including stony meteorites called pallasites, were found at Hopewell sites.

"These micrometeorites have a chemical fingerprint. Cosmic events like asteroids and comet airbursts leave behind high quantities of a rare element known as platinum," Tankersley said. "The problem is platinum also occurs in volcanic eruptions. So we also look for another rare element found in nonterrestrial events such as meteorite impact craters—iridium. And we found a spike in both, iridium and platinum."

The Hopewell people collected the meteorites and forged malleable metal from them into flat sheets used in jewelry and musical instruments called pan flutes.

A magnet holds tiny micrometeorites collected from sediment samples taken from an ancient Hopewell site. Researchers say this evidence points to a comet airburst that devastated parts of the Ohio River Valley more than 1,500 years ago. Credit: Michael Miller

Beyond the physical evidence are cultural clues left behind in the masterworks and oral histories of the Hopewell. A comet-shaped mound was constructed near the epicenter of the airburst at a Hopewell site called the Milford Earthworks.

Various Algonquin and Iroquoian tribes, descendants of the Hopewell, spoke of a calamity that befell the Earth, said Tankersley, who is Native American.

"What's fascinating is that many different tribes have similar stories of the event," he said.

"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," he said.

"The Shawnee refer to a 'sky panther' that had the power to tear down 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."