In July 1962 , the US carried out the Starfish Prime test , exploding a 1.44 megaton bomb above the mid-Pacific Ocean . This demonstrated that the effects of a high-altitude nuclear explosion were much larger than had been previously calculated . Starfish Prime made those effects known to the public by causing electrical damage in Hawaii , about away from the detonation point , knocking out about 300 streetlights , setting off numerous burglar alarms and damaging a microwave link
Starfish Prime
Starfish Prime
Nuclear electromagnetic pulse