Is There Anybody Out There?

JILL Tarter has two claims to fame. Not only is she one of America’s most respected space scientists, she was also the model for the heroine of a blockbuster Hollywood film. When Jodie Foster graced the silver screen in Contact, as the head of a programme trying to locate alien signals from the cosmos, it was Tarter’s story she was bringing to life.

Despite the Hollywood hype, the scientist nevertheless retains her reputation for hard-headed science. Asked recently by a children’s magazine if a breakthrough was imminent, she took the pragmatic view. “Chances are the search will take a long time,” she replied. “I hope there are readers out there who might want to be my replacement someday.”

Last week it emerged that she may no longer have any need for a successor. Scientists working for Tarter’s US-government funded Search for Extra-terrestrial Intelligence Programme (Seti), announced they had tracked an unexplained radio signal that was the best candidate yet for “first contact” from an alien civilisation.

The strange signal had been picked up three times by the giant Arecibo radio telescope in Puerto Rico that Seti uses to scour outer space. That the signal did not carry the tell-tale signature of any known astrological phenomenon, or couldn’t be the result of natural interference, only added to the global sense of excitement.

Originating from the region of space between the constellations Pisces and Aries, it was also recorded on the frequency that most theorists of extra-terrestrial intelligence believe aliens would be most likely to transmit on if they were trying to make contact with another civilisation.

Inevitably the finding, despite Tarter and Seti’s impeccable credentials, drew as much raucous criticism as it did academic support. Critics said it came from a region where there were no obvious stars or planets for thousands of light years around, and that it was very weak.

But no-one suggested that even if signal SHGb02+14a proves to be a dud, the search should not go on. If there is anyone out there then we – from scientists to philosophers to Joe Public – want to know about it.

“I think it is psychologically very important that we get out there and look for signs that we are not alone. It’s is one of the most exciting things the human race can do,” said Don Kurtz, professor of astrophysics at the University of Lancaster. “How we will deal with it if we find it throws up a whole different set of questions.”

For John Brown, head of the department of physics and astronomy at Glasgow University and Scotland’s Astronomer Royal, it was one small step towards achieving one of his greatest wishes before he shuffles off this Earth.

“Some years ago colleagues at Jodrell Bank found what they thought were pulsars (pulsating stars) and later discovered the signal they were getting was a fault with a timing clock. However, not very long afterwards they found that pulsars were real,” Brown said.

“Likewise, the Seti signal may turn out to be spurious, but next time it might not be. I would love to see some sort of sign of life out there in my lifetime. Ideally it would be intelligent, but even if its just a tiny microbe then the chances of other people out there go up greatly. That’s why we have been searching for extra- terrestrial life for a long time now. But now we are getting better at it.”

Perhaps surprisingly, the search for extra-terrestrial life starts here on Earth. Most scientists agree that if life does exist somewhere in space then it is more likely to be in microbial form than a green skinned, twin-headed, pointy-eared creation of science fiction.

“This stands to reason as most life on Earth is microbial,” Kurtz said. “Why should it be different anywhere else?” Hence the scientific hunts in some of the world’s most inhospitable places, exploring the theory that if life can survive extreme heat, cold or pressure on Earth, then it might also be thriving on another planet in similar conditions. If we know what to look for, the chances of finding it are greater.

Marine biologists from the American Woods Hole Oceanographic Institution are still penetrating the mysteries of the huge ocean- floor geysers that spew out water heated to 700 degrees Fahrenheit, filled with toxic hydrogen sulphide, the gas that smells like rotten eggs.

The geysers, a mile and half down on the floor of the Pacific, were discovered in 1977 along with a then unknown but thriving colony of small organisms. It’s one of the harshest environments on Earth and yet life is still abundant. Similarly, there is the boiling, acidic hell of the geysers of Yellowstone National Park, which are nevertheless brimming with microscopic life.

Organisms have also been discovered that survive incredible amounts of radiation and others that live in extreme cold. Extreme heat is the province of the Atacama Desert in Chile, a largely- lifeless environment except for legions of Nasa scientists looking for previous signs of life before the terrain became too harsh for an unknown geological reason.

The Nasa teams are interested because if they can find out why the Atacama died, the lessons can be applied to Mars. The Atacama is the nearest we have on earth to the dry, dusty Martian landscape.

Nasa geologist Chris McKay says: “The more we understand about life on Earth – its limits, its capabilities, the record it leaves behind – the more we’re in a position to do a search somewhere else. Really, the proper place to learn about life is Earth. We have no choice and that’s where we are – and that’s the knowledge we need to go search on Mars.”

Not that we aren’t already there of course. Earlier this year two robots, Spirit and Opportunity, followed the ill-fated European Beagle mission 37 million miles on to the surface of the legendary Red Planet and survived.

Above all else, they are looking for signs of water. Opportunity has already found strong evidence that water once flowed on Mars at a time in the past when it was warmer.

Water is necessary for life and it is what scientists are probing for both on Mars and beyond. This means outside our solar system where the hunt is already on for Earth-size planets in the right place within their own solar systems – in the so-called habitable zone.

Such a planet has not yet been discovered, but last month another giant leap towards finding extra-terrestrial life was made. Nasa astronomers said they had found the smallest planets yet orbiting stars beyond our Sun.

They are two to three times the diameter of Earth – the size of Neptune. The theory is that there is no reason why planetary systems located around other stars should not have the same assortment of heavenly bodies as our own.

“We can’t quite see the Earthlike planets yet but we are seeing their big brothers,” said Paul Butler of Washington’s Carnegie Institute.

Cue Kepler and Eddington. Kepler is a Nasa-bankrolled space telescope that will launch from Cape Canaverel in 2007. Basically a complicated light meter, it will orbit the Sun on roughly the same trajectory as Earth. Its mission is to spend four years staring at the same 100,000 stars and spot replica Earths.

It at least will not be alone. Eddington, named after illustrious 1930s British astronomer Arthur Stanley Eddington, is the European Space Agency’s GBP 115m equivalent. Due for launch in 2008, it will hover beyond the Moon and gaze at the Milky Way with exactly the same mission. By measuring tiny changes in the brightness of distant stars, Earth clones may be spotted.

Once that happens, space scientists say, the race will be on to find out whether the conditions for life are present.

By that time, technology may well be providing clues as to what to look for from nearer to home. Beneath the thick ice that covers Europa, a moon of Jupiter, is believed to lie a deep ocean. It is possible that, like in extreme conditions on Earth, life huddles there.

A probe, with a plutonium core, could be sent there to land on and melt through thin ice into the depths below. “There could be deep sea vents like those on Earth with their own ecosystem,” said Kurtz. “The probe would be able to take readings and we just have to wait and see what pops up.”

Meanwhile, as we look for life out there, Seti will be continuing, funds permitting, its lonely vigil waiting for aliens to make contact with the human race.

Whatever else its signals of September 2004 will do, they will give encouragement to alien-spotters everywhere.

Ron Halliday, who has been investigating UFO sightings in Scotland for more than 20 years and has written several books on the subject, said: “It will provide hope for many people who may be feeling they have been whistling in the dark for many years, that respected scientists are giving credence to the theory that there is something else out there.”

The rest of us, with the lack of firm evidence, can still sit on the fence. But psychologists suspect the need to believe in intelligent extra-terrestrial life spans back centuries and is deep- rooted in almost everyone.

“People look at their lives and the world and come to the conclusion that there has to be more out there than what they can observe personally,” said Dr Peter Lamont, a research fellow attached to the department of psychology at the University of Edinburgh.

“For some that is expressed in religious belief, but there are others who prefer to believe that there is alien life. The interesting thing is that scientists are starting to back this up with evidence. How you interpret that depends on what you believe.”