Duncan Lorimer will never forget the moment he stumbled upon one of the great new mysteries in astronomy. The English radio astronomer at West Virginia University had asked an undergraduate, David Narkovic, to comb through pulsar survey data from the Parkes Observatory in Australia. One fateful day in 2006, Narkovic walked into Lorimer’s office with evidence of an unusual observation: a pulse of radio waves from the sky unlike any seen before. It was among the brightest observations ever in radio astronomy, originating from billions of light-years away, and it lasted just a few milliseconds. “I was speechless,” Lorimer recalls. “To be honest, I didn’t know what to make of it.”
Lorimer and Narkovic had uncovered the first fast radio burst, or FRB. It was a total surprise to them; the idea of radio wave bursts had been abandoned after scientists in the ’70s and ’80s failed to locate such signals. Only a handful of them (11 at last count) have been observed since their discovery nine years ago, and they remain unique. Many astronomers think they come from outside the galaxy, but beyond that, their origins remain mysterious. As novel as FRBs are, however, they are just the latest example of a sporadic but always exciting moment in science: an unexpected discovery of an anomaly in the expected data.