Edison shows off his phonograph, atom bomb testing heads underground, a chimpanzee orbits the Earth, the Pong craze begins, and the world loses another Beatle, all on this day.
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National Nuclear Security Administration
1951: The first U.S. underground atom bomb test is detonated at Frenchman Flat, a 123-square-mile dry lake bed at the Nevada Test Site. The 1.2 kiloton explosion, codenamed "Uncle" as the last of a series of seven tests termed Operation Buster-Jangle, takes place 17 feet underground and leaves behind a hole 53 feet deep and 260 feet wide.