K2-18b: the exoplanet that could have signs of life
Scientists may have discovered evidence of farts from alien marine creatures 120 light years away

The tantalising prospect that we might not be alone in the universe is a step closer to reality thanks to the discovery of a possible sign of life on a distant planet.
Nasa's James Webb Space Telescope may have found a molecule called dimethyl sulphide (DMS) on a planet called K2-18b. This is significant, the BBC said, because "on Earth, at least, this is only produced by life" – specifically, according to experts, in the form of farts from marine creatures.
Data from the massive telescope also suggests the exoplanet, the name for a planet outside the solar system, may also have a surface covered in water and an atmosphere rich with hydrogen.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
Despite the excitement, scientists have stressed that the discoveries on the planet that sits 120 light years away are "not robust" and will require significantly more research to confirm.
What and where is K2-18b?
K2-18b orbits the dwarf star K2-18 in the constellation Leo around 120 light years from Earth.
In size, it sits between Earth and Neptune, but what makes it most interesting to scientists is that it demonstrates traits astronomers refer to as "Hycean" – a combination of hydrogen and ocean. According to Nasa, Hycean planets are good candidates for searching for life beyond Earth.
The star it orbits is much cooler than our Sun but because it sits closer to its star, it is in what is known as the "habitable zone", explained Brad E. Tucker, an astrophysicist at Australian National University, on The Conversation. "This is the area that is not too hot and not too cold, where liquid water can exist (instead of freezing to ice or boiling into steam)".
Is this a sign of life?
For many commentators, the most exciting of the findings was the possible detection of the DMS molecule.
Professor Nikku Madhusudhan, of the University of Cambridge, who led the research, told the BBC that his entire team were "shocked" when they saw the results.
"On Earth, DMS is only produced by life. The bulk of it in Earth's atmosphere is emitted from phytoplankton in marine environments," he said.
Specifically, DMS is created through flatulence from marine life and plankton, said Tucker in The Conversation. "So yes, scientists are excited by the potential idea of alien marine farts."
What next?
The possible observation of DMS on K2-18b "remains preliminary", said Smithsonian magazine.
"Upcoming Webb observations should be able to confirm if [dimethyl sulfide] is indeed present in the atmosphere of K2-18 b at significant levels," Madhusudhan said in Nasa's statement.
And while the new data suggests an ocean of water might sit below the exoplanet's atmosphere, it is still possible that the ocean may be too hot either to be liquid or for life to survive.
Additionally, K2-18b would need to have a rocky surface in order for liquid water to sit on it. "It might have a rocky surface, but it is more likely a giant ball of liquid and gas, like Neptune," Nasa wrote in 2019.
The Cambridge team will now continue to observe K2-18b "as they aim to validate their findings and also gather more intel about the environmental conditions on the exoplanet", said Space.com.
"Our ultimate goal is the identification of life on a habitable exoplanet, which would transform our understanding of our place in the universe," Madhusudhan said. "Our findings are a promising step towards a deeper understanding of Hycean worlds in this quest."
Sign up for Today's Best Articles in your inbox
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Arion McNicoll is a freelance writer at The Week Digital and was previously the UK website’s editor. He has also held senior editorial roles at CNN, The Times and The Sunday Times. Along with his writing work, he co-hosts “Today in History with The Retrospectors”, Rethink Audio’s flagship daily podcast, and is a regular panellist (and occasional stand-in host) on “The Week Unwrapped”. He is also a judge for The Publisher Podcast Awards.
-
Today's political cartoons - April 1, 2025
Cartoons Tuesday's cartoons - trade wars, tax deadlines, and more
By The Week US Published
-
The ETA: how new UK travel rules may affect you
The Explainer Full roll-out of Britain's new travel scheme is designed to be easy, but some have already faced problems
By Rebekah Evans, The Week UK Published
-
Arts on prescription: why doctors are prescribing museums and comedy
In The Spotlight Stressed-out patients in Switzerland are being prescribed a trip to the museum to boost their mental wellbeing
By Chas Newkey-Burden, The Week UK Published
-
We could be living in a black hole
Under the radar And our universe may not be the only one
By Devika Rao, The Week US Published
-
Dark energy may not doom the universe, data suggests
Speed Read The dark energy pushing the universe apart appears to be weakening
By Peter Weber, The Week US Published
-
Chile's stargazing 'dark skies' are under threat
Under The Radar New chemical plant could spoil celebrated astronomical stronghold
By Chas Newkey-Burden, The Week UK Published
-
Life after space: how will Nasa's stranded astronauts cope?
In the Spotlight Sunita 'Suni' Williams and Barry 'Butch' Wilmore are headed back to Earth after nine months on the ISS – but their greatest challenge may still lie ahead
By Harriet Marsden, The Week UK Published
-
Killer space rocks
Feature The threat to Earth from a newly discovered asteroid has faded. Others could be headed our way.
By The Week US Published
-
Full moon calendar: dates and times for every full moon this year
In depth When to see the lunar phenomenon every month
By Devika Rao, The Week US Last updated
-
The shape of Earth's core is changing
Under the radar Mysteries remain at the center of the planet
By Devika Rao, The Week US Last updated
-
How worried should we be about asteroids?
Today's Big Question Odds of asteroid 2024 YR4 hitting Earth have fluctuated wildly this week
By Chas Newkey-Burden, The Week UK Published