First Nuclear Explosion

In the early 1940s, the United States developed physical principles of nuclear explosion known as the Manhattan Project. The test was conducted in the Jornada del Muerto desert about 35 miles (56 km) southeast of Socorro, New Mexico on what was then the USAAF Alamogordo Bombing and Gunnery Range (now part of White Sands Missile Range). The explosion was felt over 100 miles (160 km) away, and the mushroom cloud reached 7.5 miles (12.1 km) in height. Two atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki in August 1945. One hundred and forty thousand people were killed in Hiroshima and seventy-five in Nagasaki. The cities themselves were turned to ashes. It was the first time nuclear weapons had been used in human history.