Aliens will attack Earth, Stephen Hawking claims

Professor Stephen Hawking, the renowned British astrophysicist, has long claimed that aliens are out there. But in a new documentary he argues against seeking them out, warning that advanced extraterrestrial life forms would aggressively seek to colonise Earth should humans ever make contact with them.

Hawking claims that, while most alien life is likely to consist of small animals or microbes, it is entirely possible that species also exist which are far more intelligent and aggressive than humans. Trying to interact with such beings would be "too risky" and would inevitably lead to an invasion of Earth.

In Stephen Hawking's Universe, which airs in Britain on the Discovery Channel from May 9, the 68-year-old professor likens a potential visit by aliens to that of Christopher Columbus arriving in the Americas. "[That] didn't turn out very well for the Native Americans".

The first episode sees Hawking outline how Earth could be attacked by "massive ships" sent to plunder its resources, in what sounds like a plot from Doctor Who. "We only have to look at ourselves to see how intelligent life might develop into something we wouldn’t want to meet... Such advanced aliens would perhaps become nomads, looking to conquer and colonise whatever planets they can reach."

Hawking, who has motor neurone disease and speaks through a voice synthesiser, spent three years working on his new TV series.

It is by no means the first time Hawking has expounded his theories on the existence of alien life forms. For him, the logic is simple, he said in an interview this weekend to publicise the new series. Given that there are 100 billion galaxies it is highly unlikely that Earth could be the only planet where life has evolved.

"To my mathematical brain, the numbers alone make thinking about aliens perfectly rational," he told the Sunday Times. "The real challenge is to work out what aliens might actually be like." ·