He may have expected the results, but that didn’t leave him any less astonished by what he found.

Avery Broderick knew that the first black hole ever observed by human technology was likely to be perfectly round. After all, that’s what Albert Einstein had predicted a century ago.

But when Broderick first saw the image he and other researchers affiliated with the Event Horizon Telescope Collaboration had compiled based on data from eight telescopes, he was awestruck.

“I was a little stunned that it matched so closely the predictions that we had made,” he said Wednesday.

Broderick was one of five experts to speak at a press conference in Washington, D.C., revealing the photo to the public for the first time. He is an astrophysicist at the Ontario-based Perimeter Institute for Theoretical Physics, which is one of the 13 organizations behind the Event Horizon Telescope Collaboration, and the University of Waterloo.

He explained the fiery ring of light seen around the black hole in the image, noting that it comprised photons moving through “the most extreme environment in the known universe” as they attempted to travel around the black hole powering the M87 galaxy 53 million light years away from Earth.

Feeling a tug from the black hole’s strong gravitational field doesn’t automatically mean the photons will disappear into the black hole, Broderick explained. If the photons manage to move past the black hole without crossing its “event horizon” – the point past which nothing can escape – they will be able to continue their journey through the galaxy.

Broderick said that the image proves that supermassive black holes are “analogous in important ways” to smaller black holes, which are better understood by scientists.

The circular nature of the black hole in the image also helps confirm Einstein’s theory of general relativity, which predicted that shape.

“Were Einstein wrong … its silhouette could have been very different,” Broderick said.

While Broderick said he was “not terribly surprised” by the discovery given the “long history of Einstein being proven right” on issues around general relativity, he expressed hope that Wednesday’s announcement would lead to new scientific breakthroughs.

“The most exciting thing we could possibly do would be to supplant Einstein, to find that in this extreme gravitational laboratory, that there’s something a little new,” he said.