Royal Society meet to discuss if extra-terrestrials are here on Earth

It is the classic sci-fi scenario: discovering aliens, not in outer space, but right here on Earth, sitting next to you in the workplace, serving food in your local restaurant, or, scariest of all, in your own home.

The premise might sound like the film Men in Black, but this week it will consume the great minds of science at a meeting of Britain’s most venerable institution, the Royal Society.

Paul Davies, a physicist at Arizona State University, will suggest tomorrow that the search for extra-terrestrial life should be focused right under our noses. His audience will include representatives from Nasa, the European Space Agency and the UN Office for Outer Space Affairs, while Lord Rees, President of the Royal Society and Astronomer Royal, will also lead one of the sessions.

Addressing the meeting to mark the 50th anniversary of the Search for Extra-Terrestrial Intelligence (SETI) programme — a quest that has fallen far short of its objectives — Professor Davies will argue that demonstrating that life has appeared more than once on Earth would be the best evidence yet that it must exist elsewhere in the Universe.

He told The Times: “We need to give up the notion that ET is sending us some sort of customised message and take a new approach.”

According to Professor Davies, “weird” microbes that belong to a completely separate tree of life, dubbed the “shadow biosphere”, could be present in isolated ecological niches in which ordinary life struggles to survive. Likely hiding places include deserts, scalding volcanic vents, the dry valleys of Antartica or salt-saturated lakes.

One team, led by Felisa WolfeSimon, of the US Geological Survey, is investigating the possibility that places that are heavily contaminated with arsenic, such as the Mono Lake in California, might support forms of life that use arsenic in the same way that other life forms use phosphorus.

Not all are convinced by the “shadow biosphere” concept. Colin Pillinger, who led the Beagle 2 Mars landing mission, said: “I prefer to deal in scientific fact — this is wildly science fiction. You’d be off your trolley to go searching for arsenic-based life.”

Professor Pillinger, who is due to speak at the Royal Society today, argues that Mars remains the best bet for finding alien organisms.

The conference will also address the social implications of the search for alien life. Albert Harrison, from the University of California, Davis, will discuss how human beings might respond to the discovery of extraterrestrial intelligence.

“It is easy to imagine scenarios resulting in widespread psychological disintegration and social chaos,” he said. “But historical prototypes, reactions to false alarms and survey results suggest that the predominant response to the discovery of a microwave transmission from light years away is likely to be equanimity, perhaps even delight.”