Free Astronomy Magazine January-February 2023

32 JANUARY-FEBRUARY 2023 ASTRO PUBLISHING oration involving research staff from the Instituto de Astrofísica de Ca- narias (IAC). WASP-39 b is a planet unlike any in our solar system. It is a so-called “hot Saturn”, a planet about as massive as Saturn but in an orbit tighter than Mercury. This exoplanet was one of the first examined by Webb when it began regular science operations. The results have excited the exo- planet science community. Webb’s exquisitely sensitive instru- ments have provided a profile of WASP-39 b’s atmospheric con- stituents and identified a plethora of contents, including water, sulfur dioxide, carbon monoxide, sodium and potassium. The data also sug- gest the presence of clouds that may be fragmented rather than forming a single, uniform mantle over the planet. “We observed the exoplanet with multiple instruments that, to- by IAC − Science Communication and Culture Unit WASP-39 b’s atmosphere as never seen before W ebb has produced a mo- lecular and chemical por- trait of the atmospheric constituents of exoplanet WASP-39 b, a Saturn-sized behemoth that orbit a star some 700 light-years away. The observations provide a full menu of atoms and molecules, and even signs of active chemistry and clouds. The suit of discoveries is de- tailed in a set of five scientific papers produced by an international collab-