Starfish Prime

Making the heavens glow

On July 9th, 1962, for a nuclear test called “Starfish Prime,” the United States detonated a 1.4 megaton hydrogen bomb in outer space. The explosion occurred 250 miles above the US military’s Johnston Atoll test site in the Pacific Ocean. Stories have it that, the night of the test, some Hawaiian hotels hosted “rainbow bomb parties” to for guests to watch the effects of the blast in space, which appeared similar to the northern lights. According to one scientist who saw the detonation from Canton Island “A brilliant white flash erased the darkness like a photoflash. Then the entire sky turned light green for about a second. In several more seconds, a deep red aurora, several moon diameters in size, formed where the blast had been. A white plasma jet came slowly out of the top of the red aurora (over Johnston Island) and painted a white stripe across the sky from north to south in about one minute. A deep red aurora appeared over Samoa at the south end of the white plasma jet. This visual display lasted for perhaps ten minutes before slowly fading. There was no sound at all.”

The Starfish Prime test was part of the larger “Operation Dominic” series of nuclear test detonations carried out by the US in 1962 and 1963 in the Pacific Ocean and Nevada. Starfish Prime was part of a sub-set of Dominic tests called “Operation Fishbowl”, which explored the effects of detonating nuclear warheads at very high altitudes. The purpose of the Fishbowl tests was to evaluate whether US nuclear tipped missiles could be used to shoot down incoming Soviet nuclear warheads in space, before they could reach their targets in the US. The electromagnetic pulse (EMP) caused by the blast knocked out electronics, including hundreds of streetlights, in Hawaii, over 930 miles away. This effect, which had been unexpected, helped to awaken US nuclear planners to the use/danger of EMP pulses in warfare.

Today, Johnson Atoll is a wildlife refuge, home to many species of birds.