K2-18b is 1,000,000,000 years away by car – but will we find life there?

If you thought a long-haul flight to Australia was bad enough, try being on a plane for 139 million years.

This is how long it would take a jet travelling at 600mph to get to K2-18b, a planet that may (or may not) have alien life.

K2-18b is a massive rock that orbits a dim star 124 light-years from Earth.

Analysis of the exoplanet – a planet outside our solar system – shows that its atmosphere may contain a molecule that smells like cabbage, which, on Earth, has one source.

Life.

The University of Cambridge researchers were at pains to stress, however, that their findings published today aren’t proof that the truth is out there.

The easiest way to check if aliens are casually hanging out on K2-18b would be to visit the planet.

But don’t expect to get there anytime soon, according to Nasa.

How long would it take to get to K2-18b?

K2-18b is 124 light years away. It might not sound like much, yet just a single light year is about 5,880,000,000,000 miles.

So the planet is, give or take, 729,000,000,000,000 miles away.

The US space agency says that if you jumped into a car and travelled at 60mph, it would take you 1,000,000,000 years.

If Katy Perry were in the passenger seat – like she was on the Blue Origin earlier this week – and began belting Firework non-stop, you’d listen to the song about 131,400,000,000,000 times.

By bullet train, which zooms at 120mph, you’d be travelling for 694,000,000 years.

The Voyager, a probe launched in 1977 and among the fathers human-made objects in space, travels at a slightly faster 38,000mph.

So it would take roughly 2,000,000 years to touch ground on K2-18b.

The speediest way to get to K2-18b, of course, would be to travel at the speed of light itself – 671,000,000mph – for a travel time of 124 years.

Scientists detected a possible signature of life – what could have made it?

Given that planets like K2-18b are so far away, scientists have had to get creative to figure out what lies on their surfaces.

The Cambridge team used the James Webb Space Telescope (JWST) to study K2-18b’s atmosphere. When an exoplanet drifts past its star, its atmosphere is illuminated.

The gases change the colour of the starlight that reaches the telescope, allowing scientists to figure out the chemical composition.

In K2-18b’s case, they believe it contains dimethyl sulphide, made of sulphur, carbon, and hydrogen, along with a similar molecule called dimethyl disulfide.

Similar but far fainter findings of the molecule were made in 2023.

What kind of life could be coughing up these gases, however? Lead researcher Professor Nikku Madhusudhan says that K2-18b could be blanketed by a warm ocean and wrapped in hydrogen, methane and other carbon compounds.

This is a bit of a novel concept in the scientific world. Madhusudhan and his team dubbed this a ‘Hycean’ planet, a combination of ‘hydrogen’ and ‘ocean’.

So, tiny oceanic critters would make sense, Mike Bonsall, a Professor of Mathematical Biology at the University of Oxford, told Metro.

‘Dimethyl sulphide, which might smell like cooking cabbage, is a byproduct of many single-cell organisms in the oceans – particularly bacteria and marine algae,’ he said.

‘If this signature is confirmed, it would be strong evidence for a form of biological life, suggesting some of those evolutionary steps/transitions are achievable elsewhere in the Universe (which shouldn’t surprise us).

‘That the JWST is able to detect this sort of signature is so, so cool.’

But further studies are needed to determine whether K2-18b is even habitable, Dr Alfredo Carpineti, an astrophysicist and IFLScience senior staff writer, said to Metro.

One paper posted Sunday, for example, suggested that the planet is a lump of rock covered with magma oceans – not exactly Earth-like.

‘I feel that calling this the “strongest hints” of life is quite hyperbolic,’ he said. ‘Extraordinary claims require extraordinary evidence, and that kind of evidence is simply not there yet.

‘If there was life there, and it is a massive if, the simplest explanation would be microbial life and plankton.’

For now, scientists need to conduct more experiments to understand what today’s paper has really discovered. They’ll need to recreate the possible conditions on K2-18b to see how dimethyl sulphide acts while also studying any additional data from the Webb telescope.

Dr Caroline Harper, Head of Space Science, UK Space Agency, added to Metro: ‘Scientists like those at the University of Cambridge are using this data to try to answer one of the most important scientific questions we have: is there life out there?’

‘It is far too early to answer that question definitively, but this new research gives us a glimpse of the exciting science to come, as JWST and future missions like NASA’s Habitable Worlds Observatory allow humanity to look further, and deeper, into the cosmos.’

Chris Lintott, an astronomer and author of Our Accidental Universe, agrees.

‘We’re all so keen to find life, it’s easy to say a latest discovery might just be the thing that turns out to be aliens,’ he told Metro.

‘But so far, at least, it’s never been aliens… my guess is this is just chemistry doing its thing.’

Scientists might not be screaming aliens right now, but Mark Christopher Lee, a filmmaker and UFO researcher, feels it’ll happen one day.

‘I’m pretty sure life here is not going to look like us or the Grey aliens that UFO experiencers here have seen,’ Lee told Metro, agreeing with experts who suggest that plankton-type lifeforms could call K2-18b home, if backed up by more data.

‘The universe is around 13,800,000,000 years old and there could be life and civilisations at least 5,000,000,000 years ahead of us on Earth,’ he added.

‘These civilisations, to us, would be indistinguishable from magic.’

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