The Great Invisible Crater – Manson, Iowa
The largest crater in the United States
Manson, IA is located near the site of the Manson crater, formed by a meteorite collision that happened 74 million years ago. The crater’s existence was first discovered during an oil-drilling expedition in the 1930s. At one time, it was thought to be the biggest impact by an object from outer space in North America. The impact event was also once theorized to have led to the extinction of the dinosaurs. […]