Trinity was the first test of technology for an atomic weapon. It was conducted by the United States on July 16, 1945, at a location 35 miles (56 km) southeast of Socorro, New Mexico on the White Sands Proving Ground, headquartered near Alamogordo. Trinity was a test of an implosion-design plutonium device. Using the same conceptual design, the Fat Man device was dropped on Nagasaki, Japan, on August 9. The Trinity detonation was equivalent to the explosion of around 20 kilotons of TNT and is usually considered the beginning of the Atomic Age.