The Day the Sun Rose Twice - The First Atomic Explosion

It was just before 5:30 am in New Mexico on July 16, 1945. Most were still in slumber. Even in New York City, where the sun was already up, the world's financial capital was just starting its day.

At 5:29:45, the world was changed forever. The first atomic bomb was detonated atop a tower in the New Mexico desert, sending a mushroom cloud 5 miles into the predawn sky. The scientists that designed "Jumbo" or "the device" or "gadget" weren't entirely sure what would happen. Some speculated the earth's atmosphere might ignite. Perhaps the apocalyptic feel lent a hand in naming the test site "Trinity." (Actually the naming of the site is quite a controversy...)

Enrico Fermi, one of the scientists that worked on the bomb at Los Alamos, New Mexico during the months and years preceding the Trinity explosion, reportedly let the blast from the explosion carry bits of paper from his hand, measured the distance they traveled, and estimated the yield of the device on his slide rule.

Obviously a blast this big was hard to hide, even in the middle of nowhere. The official Army explanation was a munitions dump explosion.

Most of the information above comes from an outstanding book - the book - on the Trinity Site explosion called, aptly, The Day the Sun Rose Twice, by Ferenc Morton Szasz. I highly recommend it.

Photo credit - Los Alamos National Labs

Also, check out this eyewitness account of the explosion from the National Archives.