Aliens are out there

Researchers at Edinburgh University carried out an in-depth study of how life could have formed on other planets.

They concluded there are at least 361 intelligent civilisations in the galaxy which have the ability to communicate across the stars.

But there could be as many as 37,964 different evolved life forms, raising the possibility that the universe resembles the famous bar in Star Wars packed with a variety of alien races.

And like the extra-terrestrial of Steven Spielberg’s 1982 blockbuster ET, life on other planets could be super-intelligent and hundreds of thousands of years ahead of the human race.

Study leader Duncan Forgan, a PhD student at Edinburgh University’s school of astronomy and physics, said: “Our definition of an intelligent species is some kind of animal that has evolved to the point where it has become intelligent enough to use technology to build a radio transmitter.

“By that definition, we have been intelligent for about 80 or 90 years. We could be talking about aliens that are about the same level of intelligence as we are, or even much more advanced.

“If you look at the current information we have about planets in the galaxy, the age of those planets seems to be almost a billion years older than Earth.

“If life formed at the same time as life formed on Earth, then roughly speaking they have got an extra billion years of development.”

The researchers examined three possible scenarios by using a computer model of the galaxy. They found that if it is difficult for life to be formed but easy for it to evolve on other planets, there are likely to be 361 civilisations in the galaxy.

A second scenario where it is easy for life to be formed but it struggles to develop intelligence suggested there are 31,513 other forms of life in existence.

But if life was passed from one planet to another during asteroid collisions, as many as 37,964 intelligent civilisations could exist.

The study, published in the International Journal of Astrobiology, is the latest addition to the debate over whether we are alone in the universe.

Last month Nasa scientists said methane gas which had been detected on Mars in addition to water vapour could be evidence of life.

And Pope Benedict XVI recently declared an acceptance of life on other planets and the possibility of “extraterrestrial brothers”.

Mr Forgan predicted definitive proof of life existing on a planet outside our solar system could emerge within the next 25 to 50 years.

But he warned making contact with aliens was likely to be more difficult. “It could be hundreds of years, it could be thousands,” he said.

“What we found in our models was that although there are quite a few civilisations, the galaxy is a very big place.

“It takes so long for one civilisation to send a radio transmission to the other, because they are so far away, that this causes problems.”