Between 1951 and 1992, the United States conducted 928 atomic tests at the Nevada Test Site about 65 miles (105 km) northwest of the city of Las Vegas. Exactly one hundred of these tests were atmospheric, whose mushroom clouds could be seen for almost 100 miles (160 km), drawing fascinated tourists like a magnet to the desert city of Las Vegas. Even as far away as Los Angeles, located some 240 miles (386 km) away, as the crow files, the unearthly glow of the atomic bomb illuminated the dark sky turning night into day. These extraordinary but fairly regular events were covered in leading newspapers with photographs accompanied by nonchalant captions.

“Los Angeles had two dawns yesterday,” wrote the Times after one pre-dawn test in the 1950s. “Los Angeles Civic Center buildings by Nevada A Bomb blast, 1955,” wrote another, which writer Geoff Manaugh calls “an incredible statement in any context, stranger than science fiction.”

An atomic bomb lights up the night sky over Los Angeles City, on March 7, 1955. The glow lasted 20 seconds beginning at 5:20.