Renowned physicist and popular science communicator Brian Cox has publicly thanked YouTube for removing AI-generated deepfake videos that falsely depicted him endorsing outlandish claims about Comet ATLAS 3i. Despite the platform’s action, Cox expressed ongoing concern about the broader, long-term challenge of managing AI-created misinformation online.
Earlier this week, Cox, who is a Professor of Particle Physics at The University of Manchester and host of numerous acclaimed science documentaries, voiced his frustration on X (formerly Twitter). He specifically called out “AI-generated rubbish” featuring his likeness appearing on YouTube, which spread false narratives.
He clarified his stance with a widely viewed tweet: “The general rule is that if I appear to say something that you agree with and you are a UFO enthusiast, a flat earther, or someone who believes Comet ATLAS 3i is a spaceship, it’s fake.”
The deepfake controversy centers on Comet 3I/ATLAS, first spotted on July 1, 2025. This celestial body is particularly interesting to astronomers because, unlike most comets, it doesn’t orbit our Sun. It’s an interstellar comet, one of only a few ever observed. This means it originated from outside our Solar System and will eventually leave it, never to return. Scientists estimate 3I/ATLAS to be at least 7 billion years old, making it potentially twice as ancient as Earth and the oldest comet ever recorded.
Despite the scientific consensus, a fringe belief has emerged suggesting 3I/ATLAS could be an alien mothership performing a hidden maneuver around the sun. AI deepfakes have then capitalized on this, falsely showing prominent scientists, including Cox, supporting these theories.
Initially, Cox criticized YouTube for its slow response to reports of these fakes, stating on X, “We keep telling them and they are bloody slow.”
However, YouTube has since acted, though Cox noted the removals seemed limited to the more prominent accounts. Reflecting on the situation, he tweeted, “Thanks to @YouTube for taking down the more prominent AI accounts of me quickly – I’m not sure what the solution to this will be in the longer term. Doesn’t matter so much if it’s nonsense about a comet – but in other areas of science and certainly politics it’s clearly important. Interested to know what you think?”
Brian Cox is not the only public figure affected by this growing trend. Recently, Keanu Reeves voiced his displeasure over AI deepfakes used to sell products without his consent, calling the experience “not a lot of fun.” Reports indicate that Reeves even employs a company to actively remove such unauthorized AI imitations from platforms like TikTok and Meta.
Other celebrities have also faced similar issues: Tom Hanks issued a warning in 2023 about an AI version of himself used in a dental plan advertisement. Morgan Freeman thanked fans last year for flagging AI-generated voice imitations. More recently, in May, Jamie Lee Curtis directly appealed to Meta CEO Mark Zuckerberg via Instagram, frustrated by her inability to remove an unauthorized AI-generated ad featuring her likeness.
To unequivocally set the record straight on the celestial object, Cox emphasized that ATLAS 3i is unequivocally a comet, not a spaceship.
“Just to be clear – given recent online drivel – Comet 3I/Atlas is a comet, made of carbon dioxide and water ices and bits of other stuff,” he tweeted. “It is entirely natural in origin, its orbit is as expected and it will whizz around the sun and then disappear off into the galaxy again. If it ever encounters another inhabited solar system in the far future I hope the living things there are more sensible than us and enjoy it for what it is – a visitor from elsewhere in the galaxy – a pristine lump of rock and ices which formed around a distant, maybe long-dead star billions of years ago and many light years away, just passing through. Isn’t that wonderful enough?”
This article was reported by Wesley Yin-Poole, a Director of News.