Astronomers have achieved what even Einstein thought impossible and taken the first-ever image of a black hole.
Lurking at the centre of a distant galaxy named M87, the object has a mass over 6 billion times that of the sun and a gravitational field so intense not even light can escape its clutches.
Even so, astronomers have revealed its presence using a global network of telescopes that show its devastating effect on its surroundings.
The gravity of the black hole tears apart passing stars, creating a white-hot disc of debris around it. While the black hole itself remains invisible, the image shows the "ring of fire" predicted by theory.
Getting this first-ever image has pushed astronomical technology to its limit.
The supermassive black hole is as big as our solar system, but lies over 500 billion, billion kilometres away, so that as seen from Earth it is the size of a DVD on the moon.
Speaking on Wednesday, Professor Heino Falcke, of Radboud University in the Netherlands, who was involved in the experiment, described it as "an absolute monster, the heavyweight champion of black holes in the Universe".
"Although they are relatively simple objects, black holes raise some of the most complex questions about the nature of space and time, and ultimately of our existence," he told BBC News.
The announcement is the result of over a decade of work by an international team led by Shep Doeleman of the Harvard-Smithsonian Centre for Astrophysics in Massachusetts.
By linking together radio telescopes from the US and Europe to Antarctica, they have have effectively created a single telescope as big as the Earth, with the ability to glimpse the presence of the black hole.
"We have achieved something presumed to be impossible just a generation ago," he said.
"Breakthroughs in technology, connections between the world's best radio observatories, and innovative algorithms all came together to open an entirely new window on black holes."
The network is known as the Event Horizon Telescope (EHT), after the region of space that surrounds the black hole. Any object falling into the event horizon cannot escape, even travelling at the speed of light.
Instead it is dragged down into the so-called singularity at the heart of the black hole.
What happens there is a complete mystery. Even Einstein’s theory of gravity – currently the best available – breaks down at the singularity.
Ironically, while Einstein himself never believed black holes could exist, his theory of general relativity has played a key role in the design of the EHT and the interpretation of today’s results.
These are about more than taking cosmic happy snaps, however. The supermassive black hole at the core of M87 gives scientists the chance to test Einstein’s theory in conditions of incredibly intense gravitational fields.
According to Dr Doeleman, preliminary measurements suggest that the image is exactly what Einstein’s theory predicts.
However, most theorists believe Einstein’s theory cannot be the last word on space, time and gravity. Any flaws it contains are likely to show up in the behaviour of black holes.
The EHT may also cast light on the mind-boggling idea that some black holes may be portals to other universes.
According the Einstein’s theory, the singularity at the heart of a black hole can sometimes turn into a “wormhole” that tunnels through space and time.
Despite being hidden inside the black hole, some theorists claim that the existence of a wormhole may reveal itself in subtle differences in the way black holes affect their surroundings.
Such effects might soon be detectable by the EHT, which is already being upgraded to make it more powerful.