When astronomers turn our radio telescopes out towards space, we sometimes detect sporadic bursts of radio waves originating from across the vast expanse of the universe. We call them “radio transients”: some erupt only once, never to be seen again, and others flicker on and off in predictable patterns. We think most radio transients come from rotating neutron stars known as pulsars, which emit regular flashes of radio waves, like cosmic lighthouses. Typically, these neutron stars spin at incredible speeds, taking mere seconds or even a fraction of a second to complete each rotation. Recently, we discovered a radio transient...