Astronomers in Canada have detected a mysterious volley of radio waves from far outside our galaxy, according to two studies published Wednesday in Nature.
What corner of the universe these powerful waves come from and the forces that produced them remain unknown.
The so-called repeating fast radio bursts were identified during the trial run last summer of a built-for-purpose telescope running at only a fraction of its capacity.
Known by its acronym CHIME, the world's most powerful radio telescope -- spread across an area as big as a football pitch -- is poised to detect many more of the enigmatic pulses now that it is fully operational.
Fast radio bursts (FRBs) flash only for a micro-instant, but can emit as much energy as the Sun does in 10,000 years. Exactly what causes these high-energy surges of long waves at the far end of the electromagnetic spectrum remains the subject of intense debate.
More than 60 bursts have been catalogued since 2007, but only one other -- observed in 2012 at the Arecibo Observatory in Puerto Rico -- was a repeater.
Cosmic convulsions created by the turbulent gas clouds that give rise to stars, or stellar explosions such a supernovae, are both possible incubators.
But consecutive radio bursts are a special case.
It is not yet clear whether the breeding grounds of repeating bursts are different from those that produce only a single radio pulse.
Significantly, the 2012 and 2018 "repeaters" have strikingly similar properties.