Biosignatures On K2-18 B?
Madhusudhan et al. just reported ~3 sigma detection of dimethyl sulfide (DMS) or dimethyl disulfide (DMDS) in the atmosphere of K2-18 b in the Astrophysical Journal Letters. The claim is intriguing, as these gases can be associated with biological activity. On the other hand, the signal is modest, ambiguous, and potentially explainable as the result of noise or systematic error. Moreover, abiotic sources for these compounds do exist, and even if they are low-yield and short-lived, they cannot y…