On July 16, 1945, the first test of an Atomic Bomb was conducted as part of the Manhattan Project. The test detonation occurred at the Trinity site near Alamogordo, Socorro County, New Mexico. The explosion of this first atomic bomb produced a blast equivalent to eighteen thousand tons of TNT. The resulting fireball that scorched the desert formed a depressed crater 800 yards in diameter, glazed with a light olive green, glass-like substance where the desert sand had melted and re-solidified. This glassy residue is called Trinitite.