There IS intelligent life out there in our galaxy

...just down here it’s lacking, then

WE are not alone… there are 36 alien civilisations within the Milky Way, scientists reckon.

But we are unlikely to be able to visit ET or even “phone home”, as the average distance to such civilisations is 17,000 light years – too far for our technology.

The distance also makes it “very difficult” to detect them, researchers said.

They made their estimate based on the assumption that intelligent life develops on other planets in a similar way to life on Earth.

Astrophysics professor Christopher Conselice, who led the University of Nottingham team, said: “The idea is looking at evolution, but on a cosmic scale.”

However, finding such civilisations depends on how long they are actively sending out signals of their existence into space, such as radio transmissions from satellites or television.

Our own “technological civilisation”, for example, has so far lasted 100 years.

The team based their calculations on the “strong” Astrobiological Copernican Limit. This says communicating civilisations form in less than five billion years – such as on Earth, where it took 4.5 billion – while the “weak” limit puts it at more than five billion years.

Dr Tom Westby said: “In the strong criteria, whereby a metal content equal to that of the Sun is needed, we calculate that there should be around 36 active civilisations in our galaxy.”

If intelligent life is found, it could help us learn how long our own existence will continue, the team said.

Professor Conselice added: “Searches for extra-terrestrial intelligent civilisations not only reveal the existence of how life forms, but also gives us clues for how long our own civilisation will last. If

Scientists reckon ET is out there we find that intelligent life is common then this would reveal that our civilisation could exist for much longer than a few hundred years.

“Alternatively, if we find that there are no active civilisations in our galaxy it is a bad sign for our own longterm existence. By searching for extraterrestrial intelligent life – even if we find nothing – we are discovering our own future and fate.”

It has previously been “very challenging” finding good estimates of possible extraterrestrial civilisations, said the team, who published their findings in The Astrophysical Journal.

36 intelligent civilisations throughout our galaxy, the team estimates

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