A distant planet orbiting a star 700 trillion miles away may show the first real signs of alien life. Scientists at the University of Cambridge have detected potential biosignatures in the atmosphere of K2-18b, using NASA’s powerful James Webb Space Telescope (JWST) data.
The planet, more than twice the size of Earth, has long intrigued astronomers for its potential habitability. Now, researchers say they’ve found chemical traces of molecules—dimethyl sulphide (DMS) and dimethyl disulphide (DMDS)—that on Earth are produced only by living organisms such as bacteria and phytoplankton.
This marks the second time these chemicals have been observed in K2-18b’s atmosphere, but the current results are stronger and more promising. Still, the team stresses that the findings are not yet definitive. The detection’s statistical confidence is 99.7%, well short of the 99.99999% standard typically required to confirm a scientific discovery.
Even if the presence of these molecules is verified, their origin remains uncertain. While life is one explanation, some astronomers suggest unknown geological or atmospheric processes could also produce them.
The planet’s structure also remains debated. Some believe K2-18b may host a vast liquid ocean, supported by the lack of ammonia in its atmosphere. Others argue it could be a molten world or even a mini gas giant without a solid surface—both scenarios unlikely to support life.
Source: BBC