Edinburgh, Fife & East Scotland

UK Centre for Astrobiology: Is there life out there?

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Media captionThe centre has created a laboratory a kilometre beneath the Earth's surface

There are billions of stars in our own galaxy and billions more galaxies beyond. Does that mean there is a good chance of finding life beyond Earth?

That is one of the big questions the UK Centre for Astrobiology was set up to answer.

Its official launch is in Edinburgh on Tuesday, although it has already attracted 40,000 students online.

However, they are not looking for little green men. The centre's leader, Professor Charles Cockell, wants to make that clear.

"Astrobiology isn't about hunting for alien life," he said.

"It's about asking a question: Is there life beyond the Earth?"

So far the only life we know of in space is the stuff we have put there: from insects to chimps to astronauts.

There has been no sign of extra-terrestrial life, intelligent or otherwise.

"We haven't found a single micro-organism, a single bacterium beyond the Earth," said Prof Cockell.

He added: "So in terms of life beyond the Earth, astrobiology is still a field that is trying to understand whether the Earth is a unique example of life or whether we might find life elsewhere."

Tenacity of life

That is why the centre's search has begun below the ground.

It is examining the tenacity of life on Earth - where it has existed in some form or other for billions of years - for pointers to what life elsewhere might look like.

Researchers have created a laboratory a kilometre beneath the Earth's surface, at Boulby Mine in Yorkshire, to examine how organisms survive there - and what that might tell us about the possibility of life on places like Mars.

Image caption The scientists "are not looking for little green men"

Samuel Payler, a PhD student, has been helping set up the underground lab.

He said: "Because Mars's surface is pretty much uninhabitable - pretty cold, oxidising, it's a pretty tough place to live - below the surface is going to be potentially where life is going to be living there today.

"Perhaps in its past it was living on the surface, but today it's probably going to be living below ground."

Just how tenacious life can be is underlined by a glass flask the professor holds up.

Inside are microbes from space.

They came originally from a cliff face near Beer in Devon. However, they have been into orbit and back.

Extreme conditions

Small chunks of rock were chipped off the cliff face and fixed to the outside of the International Space Station.

The object was to see what, if anything, could survive the extreme conditions of space.

The flask contains small greenish specks representing the life that survived. Micro-organisms which were tough enough to survive 18 months of airlessness, radiation and extremes of temperature.

It emphasises that, should extra-terrestrial life be discovered, it is likely to look less like ET and more like the sort of stuff that grows on your shower curtain.

There exists another possibility: there is no other life out there. We are a glorious accident and quite alone.

But that doesn't worry Prof Cockell.

"A lot of people think astrobiology is some sort of hunt for life, and if we don't find life it will be a big disappointment," he said.

"But in fact that's not the case. The discovery of many lifeless planets across the Universe, the discovery that the Earth might be unique as a place for life, would be an astonishing discovery in itself.

"It would be a very lonely discovery, but it would be an astonishing discovery."

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