Atmospheric Results from JWST: Carbon Dioxide, Methane, and More?

Exoplanet discoveries have been piling up faster and faster over the last decade, limiting announcements of new discoveries to the strange, unusual, and unexpected. One unexpected type of planet is the possible Hycean world -- hot, water-covered worlds with hydrogen atmospheres larger than Earth but smaller than Neptune with sizable habitable zones. With the addition of JWST's capabilities, previously discovered exoplanets are now being analyzed for their atmospheric composition, and the results are intriguing. In a new paper accepted for The Astrophysical Journal Letters, the atmosphere of an exoplanet known as K2-18 b was found to contain carbon dioxide and methane, adding the world to the list of possible Hycean planets. Additionally, a molecule called dimethyl sulfide, which on Earth is only produced by life, was possibly detected. Join communications specialist Beth Johnson as she speaks with lead author Nikku Madhusudhan, an astronomer at the University of Cambridge, in a SETI Live at a special time. (Recorded live on 21 September 2023.) Preprint of the paper: https://arxiv.org/pdf/2309.05566.pdf