Lets hope there's nobody out there

Aliens are very likely out there, according to eminent scientist Stephen Hawking - but we should keep quiet and hope they don't notice us. Skip related content

In a new documentary for the Discovery Channel, the theoretical physicist warns against making contact with any extra-terrestrials.

Professor Hawking, who retired as the Lucasian Professor of Mathematics at the University of Cambridge last year, claims such space life would only abuse Earth's resources and move on.

"We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet," he said.

"I imagine they might exist in massive ships, having used up all the resources from their home planet.

"Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach."

"If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans."

The documentary, which begins on May 9, explores the British scientist's vision of the universe.

While most aliens were in all probability simple organisms such as microbes, Professor Hawking said it would only take a few intelligent ones to spell disaster for humans.

"To my mathematical brain, the numbers alone make thinking about aliens perfectly rational," he explained.

"The real challenge is to work out what aliens might actually be like."