The picture was captured by the Event Horizon Telescope (EHT), a network of eight linked telescopes. Prof Heino Falcke of Radboud University in the Netherlands, who proposed the experiment, said that the black hole was found in a galaxy called M87.

"What we see is larger than the size of our entire Solar System," he told the BBC.

"It has a mass 6.5 billion times that of the Sun. And it is one of the heaviest black holes that we think exists. It is an absolute monster, the heavyweight champion of black holes in the Universe."

Prof Falcke describes what we see in the image as an intensely bright "ring of fire," surrounding a perfectly circular dark hole. Interestingly, the bright halo is caused by superheated gas falling into the hole. And since the light is brighter than all the billions of other stars in the galaxy combined, it can be seen all the way from Earth. The edge of the dark circle at the centre is the point at which the gas enters the black hole, and this object that has such a strong gravitational pull, not even light can escape.

And this brings us to the definition of the black hole.It is a region of space from which nothing, not even light, can escape. Contrary to what their name might suggest, they are not empty but instead consist of a huge amount of matter packed densely into a small area, giving it an immense gravitational pull.

The region of space beyond the black hole called the event horizon, or a "point of no return." Beyond it, it's impossible to escape the gravitational effects of the black hole.

Prof Falcke came up with the idea for the project when he was a PhD student in 1993. At the time, no one thought it was possible. Prof Falcke, however, was the first to realize that a certain type of radio emission would be generated close to and all around the black hole, which would be powerful enough to be detected by telescopes on our planet.

He also hadn't forgotten the scientific paper from 1973 that suggested that because of their enormous gravity, black holes appear 2.5 times larger than they actually are.

Combine these two things and the impossible suddenly becomes possible.

Since no single telescope is powerful enough to take an image of the black hole, Prof Sheperd Doeleman of the Harvard-Smithsonian Centre for Astrophysics led a project to set up a network of eight linked telescopes. Together, they form the Event Horizon Telescope and can be thought of as a planet-sized array of dishes. Each of them is located high up at a variety of sites, including on volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, in the Atacama Desert of Chile, and in Antarctica.

In total, a team of 200 scientists pointed the networked telescopes towards M87 and had been scanning its heart for 10 days.