Exploding asteroid theory strengthened by new evidence located in Ohio, Indiana Space & Earth science / Earth Sciences Ken Tankersley seen working in the field in a cave in this publicity photo from the National Geographic Channel. Geological evidence found in Ohio and Indiana in recent weeks is strengthening the case to attribute what happened 12,900 years ago in North America -- when the end of the last Ice Age unexpectedly turned into a phase of extinction for animals and humans -- to a cataclysmic comet or asteroid explosion over top of Canada. A comet/asteroid theory advanced by Arizona-based geophysicist...