Trinity Test

July 16, 1945 — At 5:29 a.m., the world’s first atomic bomb was detonated at the Trinity Site in the Jornada del Muerto desert of New Mexico, ushering in the Atomic Age.

The device, an implosion-style plutonium bomb nicknamed “the gadget,” yielded the force of about 21 kilotons of TNT. The blast vaporized the 100-foot steel tower on which it sat and carved a crater in the desert floor. Sand within the blast zone fused into a green, glassy substance later called trinitite, spread thinly over more than half a mile.

Witnesses miles away described the fireball as brighter than the morning sun, and the shockwave shattered windows 100 miles distant. The age of nuclear weapons had begun.