A burst of gravitational waves struck planet Earth on January 14th, and the cause has scientists baffled.
These gravitational waves are actual disturbances in space-time that occur during moments where objects like collapsing stars or black holes collide with each other.
The burst still "seems a little too short for what we expect from the collapse of a massive star," Andy Howell, a scientist at Los Cumbres Observatory Global Telescope Network, said to LiveScience. "On the other hand, we've never seen a star blowing up in gravitational waves before, so we don't really know what it would look like."
The gravitational wave signal, picked up by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo interferometer, lasted only 14 milliseconds, and astronomers haven't yet been able to pinpoint the burst's cause or determine whether it was just a blip in the detectors.
Scientists currently speculate that the gravitational wave comes from a temporary event like a supernova explosion, though that is only a guess.
"The universe always surprises us," he added. "There could be totally new astronomical events out there that produce gravitational waves that we haven't really thought about."