How do planets start? Host Simon Steel (SETI Institute) speaks with Melissa McClure (Leiden University), lead author of a new study that caught the earliest spark of planet formation. Using JWST and ALMA, the team detected silicon monoxide (SiO)—both gaseous and likely crystalline—and pinpointed where hot, rock-forming minerals are condensing inside the protoplanetary disk of HOPS-315, ~1300 light-years away in Orion. They also map the action to a belt-like region similar to our Solar System's asteroid belt. What does SiO reveal about shocks, heat, and the first solids that seed planets? Join us to unpack the chemistry, the physics, and the cosmic "baby book" of a solar system in the making. ESO press release: https://www.eso.org/public/unitedkingdom/news/eso2512/ Nature paper: https://www.nature.com/articles/s41586-025-09163-z (Recorded live 9 October 2025.)