Brian Cox was banned by the BBC from listening to a planet – in case alien voices were overheard.
The former D:Ream star's show Stargazing Live featured a planet called Threapleton Holmes B, which had recently been discovered by two amateur astronomers, and Cox wanted to listen to the planet live on air.
But he was forbidden to do so by his bosses who wouldn't allow him to listen in case the corporation's strict editorial guidelines or health and safety rules were breached.
He told BBC 6 Music radio: "We decided that we'd point the Jodrell Bank telescope at the planet that had been discovered by these two viewers and listen because no one had ever pointed a radio telescope at it and you never know.
"The BBC actually said, 'But you can't do that because we need to go through the regulations and health and safety and everything in case we discover a signal from an alien civilisation'."
The funky physicist with the floppy fringe admitted that he was shocked at the decision because he could have made such an important discovery.
He said: "You mean we would discover the first hint that there is other intelligent life in the universe beyond Earth, live on air, and you're worried about the health and safety of it?
"It was incredible. They did have guidelines. Compliance."
BBC 6 host Shaun Keaveny added: "The idea that intelligent life could be discovered and it might swear and that's why we wouldn't broadcast it - it's such a brilliant BBC thing, isn't it?"