NASA’s James Webb Space Telescope has detected dimethyl sulfide and additional molecules in the atmosphere of the sub-Neptune K2-18 b. The new observations build on earlier 2023 measurements and intensify discussion about possible biological processes on this distant world.

Researchers note that dimethyl sulfide on Earth is primarily produced by marine organisms, making its presence on K2-18 b an intriguing lead. The planet’s hydrogen-rich envelope and liquid-water ocean beneath could create conditions where such chemistry might occur.

Scientists caution that current data remain preliminary and require further verification. Distinguishing true biological signals from unknown geological or chemical processes continues to challenge exoplanet studies.

The findings showcase how JWST is expanding the frontier of atmospheric characterization and guiding future search strategies for habitable worlds beyond our solar system.