Duncan Lorimer wasn’t looking for an eruption of radio waves from another galaxy. He and his student David Narkevic were mining old data from Australia’s Parkes Radio Telescope for oddly behaving pulsars, the rapidly spinning cores of dead massive stars. Instead, they found a strange burst of radio noise recorded in 2001 that appeared to originate well beyond one of the satellite galaxies that orbit the Milky Way.

The signal was so intense that it briefly overwhelmed the telescope. “It took me a while to come to terms with it,” says Lorimer, an astrophysicist at West Virginia University in Morgantown. “I knew it was unusual, but I just wasn’t able to grasp the whole gravity of the situation.” In 2007, Lorimer wrote in Science that the burst “represents an entirely new phenomenon.”

Just one signal was a curiosity. But in 2011, astronomer Evan Keane, who was at the Jodrell Bank Centre for Astrophysics in Manchester, England, reported a second one, also in archival data from Parkes.

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