ON SEPTEMBER 2ND 1859 C.F. Herbert, prospecting for gold in south-eastern Australia, saw something sublime in the evening sky. "A scene of almost unspeakable beauty presented itself, lights of every imaginable colour were issuing from the southern heavens," he would later recall. "The rationalist and pantheist saw nature in her most exquisite robes. The superstitious and the fanatical had dire forebodings, and thought it a foreshadowing of Armageddon and final dissolution." Those who saw cataclysm in the auroral display were not exactly wrong: just ahead of their time. The Carrington event, as the geomagnetic storm Herbert observed came to be known, was the result of loom tonnes of charged particles thrown off by the Sun a few hours earlier slamming into Earth's magnetosphere, a protective magnetic sheath generated by currents in the planet's liquid core. The electromagnetic effects of the onslaught did not just produce a truly spectacular display of the Southern Lights (and the Northern ones, too, visible as far south as Colombia). They induced powerful currents in any electrical conductors to hand. Some telegraph networks took on a life of their own, no longer needing batteries to generate signals.
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