Although John Smith and the native peoples could not have known it, the Chesapeake they explored and lived in was shaped in part by an ancient cataclysm. Thirty-five million years ago, an extraterrestrial body two to three miles in diameter, maybe a comet, maybe an asteroid, impacted the ocean-covered continental shelf of North America. The impact was near the modern location of Cape Charles, Virginia and created a crater almost as large as Rhode Island and almost as deep as the Grand Canyon. Massive tsunamis and showers of molten rock caused total devastation for hundreds of miles around. North America was a very different place at this time, with the shoreline of the Atlantic Ocean falling near the city of Richmond, Va. and the uplands covered with tropical forests.

The crater is invisible today because it is buried under hundreds of meters of sediments but its effect on the Chesapeake is still felt. The bedrock in the region was shattered nearly a mile deep by the impact, causing a subtle depression in the landscape that has influenced the course of modern rivers and helped determine the location of the mouth of the modern Chesapeake.