Comet impact may have triggered decline of Ohio’s Hopewell people 1,600 years ago

Astronomy and anthropology have blended to help determine what might have triggered the decline of a major North American society 1,600 years ago. 

A vibrant culture lived in the Ohio Valley from about 200 BCE to 300 CE. These people were the ancestors of many modern Native American tribes, such as the Haudenosaunee (Iroquois) and the Algonquin. What they called themselves remains a mystery, and they are now known as the Hopewell culture