The heat flow of a planetary body plays a major role in defining its evolution and current composition, driving processes from internal differentiation during its formation through geological activity at the current time. In this talk, I will describe how the ALMA (sub-)millimeter observatory and the James Webb Space Telescope are shedding light on the heat flow histories of satellites and small bodies. Thermal emission observations of asteroids provide information on the abundance and form of metals (ALMA) and minerals (JWST) on their surfaces. I will present ongoing asteroid programs aimed at providing a more complete compositional picture of asteroid surfaces, with implications for their heating and differentiation histories. ALMA can also measure the isotopes of the volatile-forming elements, a key tool for studying the formation and evolution of objects in the Solar System. I will discuss sulfur and chlorine isotopes in the volcanic gasses of Jupiter’s moon Io in particular, and how they place constraints on the tidal heating and volcanism that Io experienced over the age of the Solar System.

Speaker: Katherine de Kleer (California Institute of Technology)

The 2025 Fall Colloquium talks are held on Wednesdays at 3:00 PM. This colloquium is hosted by STScI and will be held as an in-person and virtual event.

You may join in person at STScI’s John N. Bahcall Auditorium or virtually on the STScI Research YouTube channel.

Please direct questions or comments to contact above. The 2025 Fall Colloquium Committee members are: Nimisha Kumari (STScI), Elena Manjavacas (STScI), Jack Neustadt (JHU), Kevin Schlaufman (JHU), Adam Smercina (STScI), Ethan Vishniac (JHU).