Link

As for Starfish Prime, because there is almost no air at an altitude of 400 kilometres, no fireball formation occurred, although manifold other notable effects did occur. About 1500 kilometres (930 statute miles) away in Hawaii, the Electromagnetic pulse created by the explosion was felt as three hundred street lights failed, television sets and radios malfunctioned, burglar alarms went off and power lines fused. On Kauai, EMP shut down telephone calls to the other islands by burning out the equipment used in a microwave link. Also, the sky in the Pacific region was illuminated by an artificial aurora for more than seven minutes. In part, these effects were predicted by Nicholas Christofilos, a scientist who had earlier worked on the Operation Argus high-altitude nuclear shots. High altitude nuclear testing leads to interesting EMP effects, which is something I have known about for a while. There is good coverage of Starfish Prime at Wikipedia and some US government hearings on the issue are interesting too. Wow. Did they really break a bunch of satellites? While some of the energetic beta particles had followed of the earth's magnetic field and illuminated the sky, other high-energy electrons became trapped in man-made radiation belts…