Project Grant 2238344

This five-year Project Grant from the National Science Foundation's Division of Astronomical Sciences, under the Mathematical and Physical Sciences program (CFDA 47.049), provides $464,583 to the California Institute of Technology to advance understanding of the long-term histories of geologically active solar system moons through isotope geochemistry. Principal Investigator Dr. Katherine De Kleer will utilize new telescope observations from the Atacama Large (Sub-)Millimeter Array to measure gases released from the interiors of bodies in the outer solar system like Jupiter's Galilean satellites. Combining these observations with modeling, the project aims to provide insight into the longevity of tidal heating at the Galilean moons, mass loss and surface-interior exchange processes at Enceladus, and the formation and migration histories of captured moons. Results will address open questions about these objects and establish abiotic isotope backgrounds, an important step toward using isotopes as biosignatures. The award also supports training students and scholars from undergraduate to postdoctoral levels in producing public-facing science content.