In 2007, astronomers Duncan Lorimer and David Narkovic discovered a strange phenomenon: A millisecond-long massive burst of energy from a single point in the galaxy, covering dozens of frequencies. It’s called a fast radio burst. or FRB. Since 2007, we’ve uncovered dozens of them. But the most recent burst to hit galactic airwaves is different: It’s an FRB that repeats.
Researchers at the University of California, Berkeley, observed that FRB 121102, that is, a burst first observed November 2nd, 2012, has been repeating again, with more pulses than ever. That’s unusual in of itself; FRBs tend to pop once, and that’s it, at least in the ten years we’ve been hunting them. FRB 121102 emanates from a dwarf galaxy roughly 3 billion light years from Earth. Fifteen new pulses, this close together, is fascinating for a number of reasons. One, it rules out a “one-time event” (i.e. something blowing up or otherwise destroying itself) as the cause of the FRB. Two, whatever happened has happened across a span of years; remember, these radio waves have to travel across space to be picked up by our telescope. And three, whatever happened, happened consistently. For all our love of the idea of a clockwork universe, it’s difficult to come up with phenomena that have this pattern.
There’s a caveat here; three billion light years away means that whatever happened in that galaxy was going on when single-celled organisms were starting to evolve on Earth. Granted, the universe is estimated to be 13 billion years old, give or take a few million, so an alien species could have gotten a big head start on us. It could also be an unusual astronomical phenomenon, like a neutron star with a powerful magnetic field called a magnetar, that we haven’t pinpointed yet, or that burned out long ago. But something strange happened, an unimaginable distance away, and no matter what the answer, it’s guaranteed to be fascinating.