Alien life on other planets could be in the form of robots who have outlived their creators, according to the Astronomer Royal.
And alarmingly, that is the same fate which may befall people on Earth too.
Numerous Hollywood films have presented the possibilities of robots becoming self-aware and deciding to destroy humans so they can rule the world.
But Martin Rees, the Astronomer Royal, told Cheltenham Science Festival robots taking over was a possibility.
On alien life, he said: ‘I think if we were to detect anything artificial I think it would not be a flesh and blood civilisation like ours.
‘I think it will be something robotic and electronic.
‘If we imagine a timeline for our Earth, it’s taken nearly four billion years for simple life to evolve into a civilisation and we’ve had technology for a few thousand years at most.
‘It’s certainly on the cards that after a few centuries more – 1,000 years – we will be superseded by electronic entities.
‘And they would be near-immortal and they could go on for the rest of the universe history.
‘So they could go on for a few billion years.’
Lord Rees told the Hay Festival last month that humans could survive on other planets by making future explorers part cyborg.