The exoplanet K2-18 b, located 124 light-years from Earth, may be an ocean world with liquid water. A new study based on data from the James Webb Space Telescope confirmed the presence of methane and carbon dioxide in the atmosphere of this super-Earth. Such gases may indicate the existence of deep water reservoirs.
Signals of molecules associated with life on Earth — dimethyl sulfide and dimethyl disulfide — were also detected. Although definitive confirmation is still lacking, their repeated detection has strengthened interest in the planet. The absence of water vapor in the atmosphere may point to a global ocean, thanks to the “cold trap” effect, in which water condenses and remains in liquid form rather than evaporating into the atmosphere.
The study of K2-18 b opens a new era in the search for life beyond the Solar System. Today it is one of the most promising candidates for habitability in the Universe.
