Intelligent life could be thriving on 40,000 planets
Science s quest to discover life on Mars has so far failed to find even one little green man.
But not to worry. Aliens could be alive and well on almost 40,000 other planets.
Researchers have calculated that up to 37,964 worlds in our galaxy are hospitable enough to be home to creatures at least as intelligent as ourselves.
Astrophysicist Duncan Forgan created a computer programme that collated all the data on the 330 or so planets known to man and worked out what proportion would have conditions suitable for life.
The estimate, which took into account factors such as temperature and availability of water and minerals, was then extrapolated across the Milky Way.
Three scenarios of how life could develop were also taken into account.
The first - that it is difficult for life to form but easy for it to evolve - concluded there are at least 361 planets harbouring intelligent life. The second, which assumed that life is easily formed but struggles to develop further, came up with a total of 31,513.
The third scenario, which assumes that life can be passed from planet to planet with the help of asteroids, saw the total rocket to almost 38,000, the Journal of Astrobiology reports.
What is more, these lifeforms would not be mere amoeba wriggling on the end of a microscope but fully-fledged aliens, because the scientists' definition of intelligent life is a species at least as advanced as humans. Mr Forgan, who believes it will take 300 to 400 years for us to make contact with our far away neighbours, said: 'I believe the estimate of 361 intelligent civilisations to be the most accurate.
'These would certainly be the most Earth-like civilisations but the bigger figures are certainly possible. We can't rule them out.
'Most of the other planets we have looked at are older than our own - so I would expect to see more advanced civilisations than ours existing.'
