One evening as the summer of 1859 drew to an end, a telegraph operator in Washington received a tremendous shock. An arc of flame burst from Frederick W Royce’s head to the equipment on his desk, and he passed out. His set was ablaze.

Wireless operators were being affected all over the world. “Everywhere the instruments were jammed,” reported the Sydney Morning Herald. Sparks from telegraph wires even created minor forest fires.

The operators suspected it was somehow related to the spectacular aurora displays the world was enjoying that week, but they couldn’t be sure. “Red spires and clouds of green” were reported in Boston.

The sky was so bright that you could read a newspaper at night, from Canada to New Zealand. The world was experiencing an electrical super storm, which was thought at the time to be a terrestrial phenomenon, a kind of high-altitude lightning.

It was only when amateur astronomers like Richard Carrington, from his home-built observatory in Redhill, Surrey, began to compare notes over the next few days that the true cause became apparent.

The sun was erupting. A phenomenon known as coronal mass ejection, or CME, had supercharged the Earth’s magnetic field, sending surges through electrical equipment.

Today, a global event of this kind is named after him: a Carrington event. Simply put, it creates massive voltages that burn out electric circuits.

“A plasma on the sun creates a magnetic field, a shock wave, and that accelerates the particles towards us,” says Prof Richard Horne, head of space weather at the British Antarctic Survey, and chairman of the official group that advises the Cabinet Office on solar electromagnetic threats.

We have a day or two’s notice that the sun has gone wild, he warns – but that’s not that useful: “Even then, you still can’t say how big the magnetic storm will be. That depends on the polarity of the magnetic field, and you can only do that with half an hour’s warning.”

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