A Cambridge team has found the strongest sign yet of potential alien life on a world known as K2-18b—a planet over twice Earth’s size, eight times its mass, and orbiting in its star’s habitable zone 124 light-years from Earth.
Using NASA’s James Webb Space Telescope, researchers spotted the molecules dimethyl sulphide (DMS) and dimethyl disulphide (DMDS), which, on Earth, are produced solely by simple marine life.
While the findings mark a significant leap from previous data, the results are still short of scientific confirmation, with a confidence level of 99.7%—shy of the 99.99999% “discovery” threshold.
The planet’s atmosphere suggests the presence of a vast ocean, but researchers caution that non-living processes might explain the gas signatures. More data is expected within the next year or two.