Black hole revealed in stunning world-first image

In a breakthrough that has helped confirm the work of Albert Einstein's theory of general relativity, scientists released the first ever image of a black hole to much fanfare on Wednesday.

For more than a century, the celestial objects had only lived in the imaginations of scientists and artists, whether shrunk down into computer models or looming large in science fiction.

The image reveals a black void staring out from a fiery ring in a galaxy 53 million light years from Earth.

Nobel Prize winner and Australian National University vice-chancellor Brian Schmidt said it was beyond Einstein's wildest dreams.

"It is truly a remarkable event for astronomy and for science," he said.

Assembled from data gathered by eight radio telescopes around the world, the picture shows light and gas swirling around the lip of a supermassive black hole, a monster of the universe first theorised by Einstein and Karl Schwartzschild more than a century ago.

Until now, black holes had only been confirmed indirectly by scientists. They are so dense that nothing, not even light, can escape their gravitational pull, making them exceptionally difficult to observe.

"We have an image of something so far away and so big that Einstein would never even have dreamed something could exist and yet it does, using the ideas he had for it," Professor Schmidt said.

The black hole is about 6 billion times the mass of our sun. Its "event horizon" - the boundary or point of no return where light and matter get swallowed into the hole - is as big as our entire solar system.

Professor Schmidt admitted he was sceptical of the project, known as the Event Horizon Telescope when it began in 2012, given the mammoth task ahead.

"I thought they'd be lucky if they ever got an image a quarter as good as what they got but sometimes science [makes progress] faster than what you think," he said.

"You needed the whole world to work together."

The picture was made with equipment that detects wavelengths invisible to the human eye, so astronomers added colour to convey the ferocious heat of the gas and dust, glowing at a temperature of perhaps millions of degrees.

At the ANU, "blackhole hunter" Christian Wolf said his own team was searching the universe for black holes which are growing, as these are ablaze with light.

But most black holes are dormant and cast only a shadow against the darkness of space, including the supermassive at the centre of our own Milky Way galaxy. 

"That strikes me as one of the hardest pictures to take, ever," he said of the image.

Astrophysicist Brad Tucker said it would allow scientists to directly measure how black holes affect gravity and time.

"I never thought we would be able to see something that has been so mysterious," he said.

Twenty-nine-year-old computer scientist Katie Bouman was behind the algorithm that made the project possible.

Compiling the snapshot used so much data it could not be sent over the internet. Scientists had to fly hard drives - including a crate from Antarctica - around the world to combine their measurements.

Black holes form when a sun dies in a supernova explosion. 

- With AP, Reuters