Elon Musk worries about the future of artificial intelligence. When speaking to Walter Isaacson, the president and C.E.O. of the Aspen Institute, on stage at Vanity Fair’s New Establishment Summit in San Francisco. Musk, the Tesla and SpaceX CEO, detailed his fears after teasing the announcement of Tesla’s secretive project called “the D.”

“I don’t think anyone realizes how quickly artificial intelligence is advancing. Particularly if [the machine is] involved in recursive self-improvement and its utility function is something that’s detrimental to humanity, then it will have a very bad effect,” said Musk.

While the scenario might sound like the storyline from an apocalyptic movie thriller, like the ‘Terminator’ series, Musk said he was worried that most people didn’t understand how fast artificial intelligence was progressing. Even the researchers in Silicon Valley might not know the full potential. The CEO expressed his concern that, in a worst-case scenario, a “super-intelligent” machine might decide to destroy human life.

“If it’s [function] is just something like getting rid of email spam and it determines the best way of getting rid of spam is getting rid of humans . . . ” Musk trailed off, as the crowd laughed.

Isaacson asked Musk if his well-publicized desire to retire on Mars, part of the inspiration behind Musk’s spacecraft company, SpaceX, could help him outrun the evil machines. Musk responded that Mars might not even be safe.

“No—more likely than not that if there’s some apocalypse scenario, it may follow people from Earth,” said Musk.

“Do you think you maybe read too much science fiction?” Isaacson asked Musk.

“Yes, that’s possible,” he said. “Probably.”