Why This Test Was Important

And why we need to "harden" our infrastructure: The 50th anniversary of Starfish Prime: the nuke that shook the world

But the effects were far more than a simple light show. When the bomb detonated, those electrons underwent incredible acceleration. When that happens they create a brief but extremely powerful magnetic field. This is called an electromagnetic pulse, or EMP. The strength of the pulse was so huge that it affected the flow of electricity on the Earth hundreds of kilometers away! In Hawaii it blew out hundreds of streetlights, and caused widespread telephone outages. Other effects included electrical surges on airplanes and radio blackouts. The EMP had been predicted by scientists, but the Starfish Prime pulse was far larger than expected. And there was another effect that hadn’t been predicted accurately. Many of the electrons from the blast didn’t fall down into the Earth’s atmosphere, but instead lingered in space for months, trapped by Earth’s magnetic field, creating an artificial radiation belt high above our planet’s surface.