When astronomy writer Christopher Crockett describes what a fast radio burst is like, he offers a whistle that swoops in pitch from high to low. “If you could hear the signal, that’s what it would sound like,” he says. He is quick to explain, though, that the eight mysterious pulses detected by two radio telescopes are actually not sounds at all. Fast radio bursts are light waves in the radio frequency range of the electromagnetic spectrum that appear to have journeyed from other galaxies. And, as Crockett explores in his story "Searching for distant signals," these unexplained signals may be trying to tell us something.