And after the event about 1,700 years ago, at a location in what is now southwestern Ohio, scientists believe the Indians created a huge terracing image of what they had seen: a striated comet.
This week, Experts from the University of Cincinnati have said that the explosion in the atmosphere of a piece of this comet – an “air explosion” – could have led to the unexplained decline of the Hopewell culture, which flourished in the eastern United States from about 100 BC to about 400 AD
Their research was published Tuesday in the journal Scientific Reports.
The team, led by anthropologist Kenneth Tankersley, described evidence of what must have been the devastation among the vast indigenous communities of the Ohio River Valley, primarily in southern Ohio.
But Tankersley said in an interview that researchers could not determine how many people may have been killed.
“Without a time machine, we can’t say for sure,” he said on Tuesday. “But everywhere we dug…we found scorched earth, hardened by fire.”
He added: “We also found burned villages.
At one site, he and his colleagues discovered “ash-covered surfaces with charcoal-filled post-molds,” they wrote.
At another site, the earth appeared to have been exposed to the heat of a blast furnace, and the limestone “had been thermally reduced to lime”, a process requiring a temperature of around 1,400 degrees Fahrenheit, they reported.
“The Ottawas talk about it as a day when the sun fell from the sky,” Tankersley said, referring to a tribe in the northeastern United States and southeastern Canada. “It would have been so brilliant. If the burst of air had happened during the day, it would have been as bright as the sun.
If a similar event has taken place over New York or Washington, D.C. today, he said, “that would be mistaken for an exploded thermonuclear device.”
The “air blow” occurred approximately between AD 252 and 383, more than 1,000 years before Europe’s major contact with the Western Hemisphere.
“It’s not the idea that the air blast killed everyone,” Tankersley said. “But rather that it was a catastrophic event” that caused the socio-economic collapse of the culture.
Tankersley said the blast was likely similar to the explosion on the Tunguska River in Siberia in 1908, which razed forests for hundreds of miles.
The Iroquois speak of a Sky Panther, Dajoji, which has the power to destroy forests. “That’s what happened in Tunguska,” he said. “It’s exactly the same.”
The Hopewells are the genetic ancestors of the Iroquois, Miami, Lenape, Shawnee and Ojibway, said Tankersley, who is a member of the Piqua tribe of Alabama.
They built “monumental landscape architecture,” the study authors write, including the world’s largest geometric earthen enclosures, water management systems and massive burial mounds.
They also had a social network that stretched from the Atlantic Ocean to the Rocky Mountains and from Canada to the Gulf of Mexico, the authors wrote.
The name Hopewell comes from Mordecai C. Hopewell, who in the 1890s owned land where a massive earthwork complex comprising 29 burial mounds was discovered outside of Chillicothe, Ohio, according to the National Park Service.
“The true tribal names of these people have been lost over the millennia,” the Park Service explains on a webpage on the Hopewell.
Tankersley said the Hopewell archaeological sites contained various materials likely from the confusing composition of a comet, which resembles a large, dirty snowball picking up debris as it travels.
One day during the third or fourth century, based on radiocarbon dating, a piece of a passing comet was shattered by Earth’s gravitational pull, he said.
It plunged into the atmosphere, where its frozen gases exploded and dumped debris onto the planet’s surface. area.
The suspected comet could have been one of 69 thought to pass Earth during that time, including Halley’s Comet, which visited in April 295 and February 374, Tankersley said.
He said excavations and research have shown that the mysterious comet-shaped earthwork in Milford, Ohio was built after the explosion because suspected comet remains were found below the level of the earthwork.
The site now sits under a local cemetery and is all but gone, Tankersley said. Corn the earthwork had a flared tail half a mile long and a head more than a quarter mile around, according to a U.S. Army Corps of Engineers map drawn in 1823.
It was also illustrated in a book published in 1848 by the Smithsonian Institution entitled “Ancient Monuments of the Mississippi Valley”.
“It’s a great example of Native Americans documenting their own history,” said Tankersley – Hopewell’s record of the disaster that may have ended his culture.