Scientists have found further evidence of possible biosignature gases on the nearby exoplanet K2-18b, strengthening the case that it could support alien life.

In 2023, researchers using NASA's James Webb Space Telescope (JWST) reported the potential presence of dimethyl sulfide (DMS) on K2-18b, which is nearly nine times more massive than Earth and circles in the "habitable zone" of a star about 120 light-years away from us.

Here on Earth, DMS is produced primarily by life — most prolifically by phytoplankton and other marine microbes — so the 2023 study was met with some enthusiasm. The excitement was tempered, however, by the preliminary nature of the find; JWST's observations were consistent with the presence of DMS but did not confirm it. So the study team looked again, but in a slightly different way this time.