The impression of an artist from K2–18 B, where researchers report signature of life activity.Credit: ESA/Hubble, M. Cornamer
A university -led team of astronomers made headlines around the world last night, claiming that they found “the strongest signs of biological activity outside the solar system”. Search includes a distant planet known as the K2-18 B, which the team says there are one or more molecules in its environment that were generated by living things1,
The announcement is with a flood of doubt from other researchers, studying such ‘biosigncares’ in the atmosphere of the exoplanet.
“This is not a strong evidence,” Stephen Schmid says, an astronomer at the University of Johns Hopkins in Baltimore, Maryland. “This is almost definitely life,” says Tessa Fisher, an astronomer at the University of Arizona in Taxon.
Here, Nature The high-profile discovery the claim-and why many scientists say that it is far from the proof of foreign life.
What has been found?
Using James Web Space Telescope, the Cambridge team reported to find signs of molecule dimethyl sulfide (DMS), a pungent smell that can be produced by bacteria, in the atmosphere of K2–18B, in the atmosphere of K2–18B, is about one planet from Earth to 38 Parasakes. Scientists detected the molecule by analyzing the starlight as it was filtered through the planet’s atmosphere; Various chemical compounds identify raids in the spectrum of light. The data related molecule may indicate the presence of dimethyl dysalfide (DMDS), either in addition to DMS or in its place1These chemicals are complicated because on earth they are manufactured by living organisms such as marine phytoplinkton.
In 2023, researchers reported similar findings2This follow -up task sees the planet in a separate set of wavelengths and a strong and cleaner indication that the molecules exist, the team says.
Researchers say that being able to tease the wide chemistry of a distant planet is a technical tour-day-force. “What we are seeing is a major paradigm change in the field of exoplanet science,” said Nikku Madhusudhan, an astronomer of Cambridge, on 17 April. He did not respond to an interview request before the press time for this story.
Why is this important?
Scientists have been looking for life beyond Earth for centuries. If DMS and DMD are present in the atmosphere of this planet, and if they are formed by biological activity, it will represent a groundbreaking moment in the discovery of extretterial life.
This work is a step towards understanding planets like K2–18 B, which is some of the 5,800-planets identified throughout the universe so far. They are referred to as ‘Mini Neptunes’ based on their mass, but beyond this, very rarely known about their makeup. Some researchers, including Madhusudhan’s team, say that some foreign water worlds may be.3If yes, they may be some of the best places to see the existence of supernatural life.
Why do other researchers suspect?
For the beginning, there are questions about whether K2–18 B also has water-or a surface where anything can remain. Modeling of IT and similar planets shows that they are probably barren5,4“A lifeless mini-neptune landscape remains the most lateral explanation,” says Joshua Chrisansen-Totan, a planetary scientist at the University of Washington in Seattle.
Then the issue is whether DMS/DMD is really present, or is it an innate signal. The measurement reported by the Cambridge team is carrying forward the range of “what JWST can actually do,” says Laura Credberg, an astronomer at the Max Planck Institute for Astronomy in Headberg, Germany.
Schmidt and his colleagues recently analyzed the 2023 claim from the Cambridge team and found no evidence of bioscnecher molecules in that data.6Schmid says that new observation are “very noise, and any reported characteristics can still be statistical ups and downs”. For their share, the researchers at Cambridge say only 0.3% likely that the signal may be due to opportunity.
