Europa, one of Jupiter’s icy moons is the most likely place in our solar system to be home to alien life
By Pallab Ghosh
Science correspondent
Many astronomers are no longer asking whether there is life elsewhere in the Universe.
The question on their minds is instead: when will we find it?
Many are optimistic of detecting life signs on a faraway world within our lifetimes – possibly in the next few years.
And one scientist, leading a mission to Jupiter, goes as far as saying it would be “surprising” if there was no life on one of the planet’s icy moons.
Nasa’s James Webb Space Telescope (JWST) recently detected tantalising hints at life on a planet outside our Solar System – and it has many more worlds in its sights.
Numerous missions that are either under way or about to begin mark a new space race for the biggest scientific discovery of all time.
“We live in an infinite Universe, with infinite stars and planets. And it’s been obvious to many of us that we can’t be the only intelligent life out there,” says Prof Catherine Heymans, Scotland’s Astronomer Royal.
“We now have the technology and the capability to answer the question of whether we are alone in the cosmos.”
The ‘Goldilocks zone’
Telescopes can now analyse the atmospheres of planets orbiting distant stars, looking for chemicals that – on Earth at least – can be produced only by living organisms.
The first flicker of such a discovery came earlier this month. The possible sign of a gas that, on Earth, is produced by simple marine organisms was detected in the atmosphere of a planet named K2-18b, which is 120 light years away.
The planet is in what astronomers call ”the Goldilocks zone’ – the right distance away from its star for the surface temperature to be neither too hot nor too cold, but just right for there to be liquid water, which is essential to support life.
Image source, NASA
Artwork: K2-18 b orbits a cool dwarf star shown in red just far enough away for its temperature to support life.
The team expects to know in a year’s time whether the tantalising hints are confirmed or have gone away.
Prof Nikku Madhusudhan of the Institute of Astronomy at Cambridge University, who led the study, told me that if the hints are confirmed “it would radically change the way we think about the search for life”.
“If we find signs of life on the very first planet we study, it will raise the possibility that life is common in the Universe.”
He predicts that within five years there will be “a major transformation” in our understanding of life in the Universe.
If his team don’t find life signs on K2-18b, they have 10 more Goldilocks planets on their list to study – and possibly many more after that. Even finding nothing would “provide important insights into the possibility of life on such planets”, he says.
His project is just one of many
