An Australian-led team scanning the cosmic melee for radio waves has discovered a mysterious object unlike anything astronomers have seen before. The object, GLEAM-XJ162759.5-523504, releases a giant burst of energy that crosses our line of sight and, roughly three times an hour, is one of the brightest radio sources in the sky.
“This object was appearing and disappearing over a few hours during our observations,” says Natasha Hurley-Walker of Curtin University, leader of the team that made the discovery. “That was completely unexpected. It was kind of spooky for an astronomer because there’s nothing known in the sky that does that.”
Unfortunately, it’s fairly clear these signals aren’t the work of little green men. As Hurley-Walker explains, the pulses of radiation come across a wide range of frequencies, which rules out an artificial signal, pointing instead to some kind of natural process we don’t yet fully understand.