Observations of Exoplanet WASP-39b show fingerprints of atoms and molecules, as well as signs of active chemistry and clouds. WASP-39 b is a planet unlike any in our solar system – a Saturn-sized behemoth that orbits its star closer than Mercury is to our Sun. When NASA’s James Webb Space Telescope initially began regular science operations, this exoplanet was one of the first to be examined. The exoplanet science community is buzzing with excitement over the results. Webb’s incredibly sensitive instruments have provided a profile of WASP-39 b’s atmospheric constituents and identified a plethora of contents, including water, sulfur dioxide,...