The true impact of an asteroid or comet crashing near the Chesapeake Bay 35 million years ago has been examined in detail for the first time. The analysis reveals the resilience of life in the aftermath of disaster. The impact crater, which is buried under 400 to 1,200 feet (120 to 365 meters) of sand, silt and clay, spans twice the length of Manhattan. The sprawling depression helped create what would eventually become Chesapeake Bay. About 10,000 years ago, ice sheets began to melt and once-dry river valleys filled with water. The rivers of the Chesapeake region converged directly over...