The asteroid-sized parent bodies of carbonaceous chondrites hosted active geologic processes, including aqueous alteration that resulted from episodes of transient heating that melted ice. Due to the role of these meteorites as contributors to planet accretion, understanding how these environments evolved is critical for reconstructing the initial conditions that shaped planetary chemistry and the origin of life. Synchrotron-based X-ray spectroscopy, specifically X-ray fluorescence and X-ray Absorption Near Edge Structure (XANES), reveals the oxidation states and coordination environments of iron at micron-scale resolution in a suite of aqueously altered carbonaceous chondrites. Of particular focus are carbonates that formed in multiple generations from evolving fluids, capturing “snapshots” of chemical change through time. These measurements enable us to reconstruct the thermal and chemical evolution of meteorite parent bodies, offering new insights into the settings that preceded planetary formation. In addition, I will briefly discuss how this application of Fe XANES to carbonates in the setting of meteorites lays a foundation for the potential use of Earth-based marine carbonates as paleoredox proxies.

Elizabeth Bailey uses numerical models of planetary orbits and interiors, together with laboratory analysis of planetary materials, to understand planetary formation, evolution, and habitability. Prior to joining the departments of Astronomy & Astrophysics and Earth & Planetary Sciences at the University of California, Santa Cruz as a Heising-Simons Foundation 51 Pegasi b Postdoctoral Fellow, she received her PhD in planetary science from Caltech. She received her bachelor's degree in mathematics from MIT, initially finding her love of planetary science during an adventure with paleomagnetic sampling in the western Himalaya. In Fall 2025, she will be starting an assistant professorship in the Department of Earth and Planetary Sciences at UT San Antonio.