Maura A. McLaughlin

The night sky is full of beacons that blink on schedule. Pulsars are fast-spinning neutron stars whose radio pulses arrive with clockwork precision. But there are other beacons too: they stay silent for minutes or hours, then suddenly emit a single pulse, and go quiet again.

Pulsars are rapidly spinning neutron stars that emit radio pulses like a lighthouse. But some of them stay silent almost all the time, occasionally emitting a single pulse. Such objects are called rotating radio transients (RRATs). They were discovered nearly twenty years ago, but they remain a mystery.