DMS hints on a distant ocean-world exoplanet spark debate over life signals

K2-18b, a sub-Neptune about 124 light-years away, is a leading Hycean candidate that could harbor a global ocean beneath a hydrogen-rich atmosphere. Webb observations yielded two tentative signals of dimethyl sulfide, a gas commonly linked to marine life on Earth, but independent analyses question whether DMS was truly detected, leaving the existence of a biosignature on the planet unresolved and highlighting the need for more data and standardized detection criteria.