The first spark of light ever detected from two massive black holes smashing into each other in the far reaches of space has been captured by world-leading British scientists.
The light was emitted when two of the galactic behemoths collided in the far reaches of space.
The top UK scientists have turned the world of astrophysics on its head with their discovery after genius Albert Einstein first predicted the existence of black holes more than a century ago.
Ever since, their gravity has been thought to be so great nothing can escape - not even light.
Now an international team has witnessed massive "flares" created by the colossal cosmic crash.
Project collaborator Dr Nicholas Ross, of the Institute for Astronomy, University of Edinburgh, said: "This result, the optical flash resulting from two black holes colliding and crushing the gas around them, is so exciting.
"As a wee kid, I was hooked by the idea of black holes and now, as a big kid, the fact that we have 'seen' as well as 'heard' these black hole mergers, is an amazing discovery that has deep implications for astrophysics."
The event involved a supermassive black hole, like the one at the centre of our galaxy, and a smaller one.
It was picked up by gravitational wave detectors LIGO in Louisiana and its European counterpart VIRGO in Cascina, Italy.
It was confirmed by the California Institute of Technology's (Caltech) Zwicky Transient Facility (ZTF), located at the Palomar Observatory near San Diego.
Previous observations have shown when two black holes spiral around each other and ultimately merge they generate ripples, or 'gravitational waves'.
The phenomena, a direct consequence of Einstein's theory of gravity, was only realised in 2015 and won three US scientists the Nobel Prize in Physics.
Lead author Professor Matthew Graham, project scientist at ZTF, said: "This supermassive black hole was burbling along for years before this more abrupt flare.
"The flare occurred on the right timescale, and in the right location, to be coincident with the gravitational-wave event.
"In our study, we conclude that the flare is likely the result of a black hole merger, but we cannot completely rule out other possibilities."
Supermassive black holes lurk at the centre of most galaxies, including the Milky Way.
They can be surrounded by a disc of flowing gas which contains swarms of stars and smaller black holes.
The flow of the gas helps to bring the smaller black holes together, enabling them to merge, and creates a larger black hole within the disk.
Upon creation, the new black hole has a large velocity and it is given what scientists described as 'a kick' through the gas disk.
Experts said it is the reaction of the gas to the new speeding black hole that creates a bright light flare, visible with telescopes.
Co author Prof Saavik Ford, of the City University of New York, added: "At the centre of most galaxies lurks a supermassive black hole. It's surrounded by a swarm of stars and dead stars, including black holes.
"These objects swarm like angry bees around the monstrous queen bee at the centre. They can briefly find gravitational partners and pair up but usually lose their partners quickly to the mad dance.
"But in a supermassive black hole's disk, the flowing gas converts the mosh pit of the swarm to a classical minuet, organizing the black holes so they can pair up."
The newly formed larger black hole, described in Physical Review Letters, should cause another burst of light in the next few years.
