The Manson impact crater, which is located near the city of Manson, Iowa, is where an asteroid or comet nucleus struck the Earth during the Cretaceous Period, approximately seventy-four million years ago. It was one of the largest known impact events to have happened in North America, and was previously thought to have led to the extinction of the dinosaurs until isotopic ages proved that it was too old.
In the recording Richard Levine given to Arby and Kelly‘s teacher, he lectures about the crater, and states that scientists now think the crater was too small by an order of magnitude, and that the current candidate is the crater near Mérida, located in the Yucatan peninsula. He incorrectly states, however, that the crater was formed sixty five million years ago, when in reality it had formed nine million years before.
