July 16, 1945. 5:29 AM Mountain Time, near Alamogordo, New Mexico. The Gadget was detonated – the 1st nuclear explosion – by the Manhattan Project. It was a plutonium implosion device. At 05:29:21 (July 16, 1945) local time, the device exploded. It left a crater of radioactive glass in the desert 10 feet (3.0 m) […]