Research Interests
Impacts and Their Effect on Planet Habitability
Impacts exemplify stochastic, high-energy events, and play a key role in shaping the chemistry of planetary atmospheres.
In my primary doctoral project, I test whether the mixing of impact vapor plumes and background atmosphere forms prebiotic species on terrestrial planets. The project contributes to understanding how impact processes perturb atmospheric chemistry, which is pivotal for assessing their astrobiological potential. I developed a coupled hydrodynamics and kinetics code to simulate the physical expansion of the plume into the atmosphere and to track the chemical reactions that occur when the plume and the atmosphere mix. Given the ubiquitous nature of impacts, the model is applicable to the Solar System terrestrial planets as well as to rocky exoplanets for which impactor flux models are available. Furthermore, the formation of prebiotic compounds can put constraints on the potential for specific projectile/target compositions to create conditions for carbon-based life to develop.
Impacts also affect planetary evolution on larger scales in space and time. I partnered with external collaborators to simulate the effect of impacts on Earth’s past climate. I tested whether impacts can induce global warming events on Earth in the last 60 Myr. I found that impactors larger than 10 km in diameter can produce a global 5 K temperature increase, and I ruled out smaller impacts (<2 km) previously associated with multi-degree global warming events found in the fossil record. In Chaverot et al. (2024), my team and I tested whether stochastic events, including impacts, can terminate the Snowball state on Earth through a runaway melting process. We found that impacts smaller than 100 km are insufficient to deglaciate the planet and escape its climate state. These joint projects advanced the understanding of the relative contribution of impact bombardment to degrading or enhancing habitability. For them, I have used hydrocode simulations with iSALE-2D coupled with radiative forcing and energy balance models.
Thermal Relaxation After Disequilibrium
Thermal evolution models help understand if and when perturbed planetary systems return to equilibrium.
I have applied these models in the context of post-impact surface temperature evolution and magma ocean crystallization. I tested whether impact-induced hydrothermal systems on Mars allow for stable surface liquid water when covered by ice, as seen at high latitudes. Preliminary results suggest that impacts ranging from 30 to 110 km in diameter can induce hydrothermal systems lasting between 0.3 Myr and 5 Myr, sufficient for mesophilic life to develop. For the project, I coupled impact hydrocode simulations with a heat diffusion model to track the crater’s post-impact temperature evolution over geologic timescales. The model addresses the influence of impact-driven hydrothermal systems on the dynamic habitability of planets.
I have been developed a magma ocean thermal evolution model to test whether non-synchronous rotation of lava worlds allows for complete magma ocean crystallization. I found that non-synchronous rotation leads to full crystallization within 100 Myr for planets that would retain a permanent magma ocean if facing their host star with the same hemisphere. Because of this project, I am currently involved in setting the protocol for model intercomparison of magma-ocean evolution codes (CHILI), which is part of the CUISINES framework.
Radiative Transfer to Constrain Disequilibrium Observations
I have used radiative transfer to suggest physical explanations consistent with observations of disequilibrium processes.
In my MSc thesis, I suggest that the long-term brightness evolution of hazes on Neptune, seen in visible HST data in 1994-2018, is consistent with variations in the H2S haze layer optical depth. The project contributes to understanding how hazes change over time to elucidate the physical processes that influence gas and its spectral properties in ice giants. I have been involved in the development of the UC Berkeley radiative transfer code SUNBEAR.
Before my graduate studies, my team and I found that isotopically lighter water outgasses from the nucleus of comet 67P at faster velocities compared to heavier water, with the velocity difference increasing as the comet got closer to the sun (Rezac et al., 2021). We suggested these different water isotopologues are formed at different altitudes from the nucleus. As part of the project, I provided a new neural network method to invert optically thick spectral lines and extract gas terminal velocities from cometary data.
Mission Formulation
Space missions enable unmatchable data collection to expand our understanding of the Universe. Reminiscent of my aerospace background, I am deeply interested in mission design, starting from the scientific question to be answered and arriving to a set of instrument and measurements that provide an answer to those questions, contributing to the advancement of the field of planetary sciences.