Dec 16, 2025
On this episode of SETI Live, host Moiya McTier welcomes two leading researchers—Gabriele Cugno (University of Zürich) & Sierra L. Grant (Carnegie Institution for Science)—to dive into an extraordinary discovery by the James Webb Space Telescope (JWST): a carbon-rich, moon-forming disk around the distant exoplanetary object CT Cha b, some 625 light-years away. What exactly is a “moon-forming disk”? Why is this discovery a game-changer for our understanding of how moons — and ultimately habitable environments around them — can form? Gabriele and Sierra walk us through spectroscopy, chemistry (including acetylene, benzene, and more), observational challenges, and the big philosophical questions: Could moons be even more common than planets? What does this tell us about our own Solar System’s past — and the possibilities for life elsewhere? 📚 For more: NASA Press Release: https://science.nasa.gov/science-research/nasas-webb-telescope-studies-moon-forming-disk-around-massive-planet/ Research Paper: https://iopscience.iop.org/article/10.3847/2041-8213/ae0290 (Recorded live 4 December 2025.)