Water is one of the key ingredients that shaped the early Solar System. It controlled chemical reactions inside small bodies, contributed to the volatile inventory of terrestrial planets, and may have provided environments where prebiotic chemistry could proceed. Yet the history of water is difficult to reconstruct, because the evidence preserved today is fragmentary: meteorites are affected by terrestrial alteration, asteroid spectra are often ambiguous, and returned samples record only limited portions of their parent bodies.
My PhD research investigates how water and other volatile species were acquired, transformed, and preserved in volatile-rich asteroids. These bodies include carbonaceous-chondrite parent bodies, C-complex asteroids, and other primitive small bodies that retain records of early Solar System processes. I combine astrophysical modeling, thermochemical calculations, and laboratory infrared spectroscopy to connect the formation of icy planetesimals, aqueous alteration inside asteroid parent bodies, and the mineralogical and spectral traces observed today.
One part of my work examines how water, ammonia, and carbon dioxide could have been delivered to asteroid-forming regions in the early Solar System. I test whether initially rocky planetesimals in the main asteroid belt could acquire volatile-rich icy pebbles as snowlines migrated inward through the protoplanetary disk.
This approach links disk evolution, pebble drift, and accretion efficiency to the present-day distribution of hydrated and possibly ammoniated asteroids. The results suggest that water delivery by icy pebble accretion is possible under some disk conditions, whereas ammonia delivery is much more restrictive. This distinction is important because ammonia-bearing asteroids may preserve information not only about local accretion processes, but also about the large-scale dynamical mixing of materials formed in colder regions of the Solar System.
Another part of my research focuses on what happened after ice melted inside asteroid parent bodies. Radiogenic heating could have produced liquid water, driving water–rock reactions and forming secondary minerals such as phyllosilicates, carbonates, sulfides, and salts. Returned samples from Ryugu and Bennu provide new constraints on this process because they contain fragile brine-related minerals that are difficult to recognize in meteorites.
I use thermochemical calculations to model the precipitation of minerals from late-stage asteroid brines. By comparing the modeled mineral assemblages with salts reported from Ryugu and Bennu, I investigate whether their parent bodies experienced different end states of aqueous evolution. The results point to low-temperature, alkaline, sodium-rich brines, but suggest different final pathways: Bennu-like materials are more consistent with evaporation or mild warming, whereas Ryugu-like materials may record freezing followed by later water loss.
Identifying spectral traces left on asteroid surfaces
A third part of my work asks how the products of aqueous alteration can be recognized remotely. Many volatile-rich asteroids show absorption features in the 3-µm region, which are linked to OH, H2O, NH-bearing materials, organics, and carbonates. In particular, the ∼3.1-µm absorption feature observed on several outer main-belt asteroids remains difficult to explain using meteorite spectra alone.
To investigate this problem, I synthesize and measure hydrated ammonium salts mixed with carbonaceous-chondrite-like simulants. Laboratory infrared spectra show that some hydrated ammonium salts can reproduce important aspects of asteroid 3-µm band shapes. This suggests that late-stage salts, possibly formed from asteroid brines, may contribute to the spectral diversity observed among volatile-rich asteroids.
Broader goal
Together, these studies follow water across multiple stages of asteroid history: delivery from the protoplanetary disk, transformation through parent-body aqueous alteration, and preservation as minerals and spectral signatures. By connecting models, samples, and observations, my work aims to clarify how primitive small bodies recorded the movement of water and other volatiles in the early Solar System, and how these materials may have contributed to the volatile inventory of Earth and other habitable worlds.