An article accepted for publication in the journal “The Astrophysical Journal Letters” reports the results of a study of the exoplanet K2-18 b, including the discovery of carbon compounds such as methane in its atmosphere. A team of researchers led by Nikku Madhusudhan of the British University of Cambridge used observations conducted with the James Webb Space Telescope’s NIRISS and NIRSpec instruments to probe the atmosphere of K2-18 b. It’s an exoplanet already considered interesting due to its characteristics and its position in its planetary system’s habitable zone. Spectral analyzes also suggest the possible presence of dimethyl sulfide (DMS), a compound considered a biomarker. These are discoveries that add to the previous ones regarding an exoplanet that led to the proposal of the Hycean class.