The James Webb Space Telescope (JWST) is the most powerful telescope ever built, but it can also act as a microscope: its infrared eyes are so sharp and so sensitive that they reveal in great detail the inner workings of molecules thousands of light-years away. In this talk, we zoom in on buckminsterfullerene, C60: a hollow cage of 60 carbon atoms shaped like a soccer ball, just one nanometre across. My team discovered these “buckyballs” in space in 2010. Quantum mechanics dictates what molecular motions are possible, and those rules leave specific fingerprints in the light molecules emit. For the first time, JWST has shown that these buckyballs not only vibrate but also rotate – and the spectra reveal that a good fraction of them have incorporated heavier carbon-13 into their cage. But JWST also revealed a puzzle. Expose C₆₀ to intense ultraviolet light in the laboratory, and it falls apart. Yet these buckyballs thrive in hot, ionized gas around a dying star, bathed in exactly that kind of light. So how do they survive? They are saved by an electron! C₆₀ grabs electrons from the surrounding gas and uses them as a kind of molecular sunscreen: when ultraviolet light strikes, it knocks off the extra electron instead of breaking the cage. Grab, lose, repeat – and that same cycle makes the buckyballs glow in the infrared. Along the way, we’ll see how observations, experiments and quantum-chemical theory come together, and what this means for other molecules in space.
Jan Cami is a Professor in the Department of Physics and Astronomy at Western University and Director of the Hume Cronyn Memorial Observatory. He co-founded the Institute for Earth and Space Exploration (Western Space) and served as its first Associate Director. He holds MSc degrees in Physics (Leuven) and Astronomy & Astrophysics (Brussels, Porto, Leiden), and a PhD from the University of Amsterdam. He worked as an astrophysicist at NASA Ames Research Center and the SETI Institute in California, before joining Western in 2006. His research combines telescope observations, laboratory data and quantum-chemical calculations to understand the physics and chemistry of large molecules in space. In 2010, he and his team discovered fullerenes (“buckyballs”) in space. He is an investigator on twelve successful James Webb Space Telescope programs, five of them as Principal Investigator. In 2023, the International Astronomical Union named asteroid (291824) Cami in his honour. A passionate teacher and science communicator, he has given many public talks and received the Canadian Astronomical Society Qilak Award for outreach (2019), a national STEAM Big! Award (2022) and Western Science awards for outreach and for excellence in undergraduate teaching.