Date of Award
Spring 2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Astronomy
First Advisor
Laughlin, Gregory
Abstract
Planetary bodies maintain records of their past and present states. These records are stored within atmospheric chemistry, interior petrology, and orbital dynamics. Often, they are corrupted by physical processes: irradiation, erosion, dynamical chaos, or collisions; or, their signatures are too weak for robust interpretation. These planetary bodies are “uncommunicative worlds.” Examples of these worlds span our Solar System’s planets, interstellar objects, and distant exoplanets. Only limited information can be gleaned by current-generation instruments. These objects require an innovative class of “planetary forensics” to elucidate their occurrence rates, formation pathways, and evolutionary histories. In this dissertation, I invent new techniques and unique combinations of existing ones to study these uncommunicative worlds. My methods draw from a common body of chemical, geological, and dynamical principles. I employ high-resolution tools, including high- spectral resolution observations, high-spatial resolution hydrodynamical simulations, and high-temporal resolution orbital integrations. I then apply these techniques within a series of case studies: • I model the transport of Venusian impact ejecta to the lunar regolith. My findings indicate encouraging prospects for recovering an ancient fragment of Venus. Such recovery would reveal whether Venus once hosted liquid oceans of water. • I determine the galactic mass burden of compact planet systems, remarkable for their uniformity in mass, radius, and orbital spacing. My analysis involves an aggregate Fourier technique inspired by cyclostratigraphy methods. Also, I implement a new model that relates stellar surface features to radial velocity perturbations, enhancing an ongoing survey of low-mass planet systems. • I refine the cross-correlation method of studying exoplanet atmospheres. I subsequently make novel detections of molecules, atoms and ions. These species have profound implications for how hot Jupiters form and the internal structures of their atmospheres. • I establish new avenues for characterizing the mysterious class of interstellar objects. The methods include in situ analysis of impact craters on the Moon and X-ray spectroscopy of solar wind Charge Exchange. I also constrain their allowed compositions using state-of-the-art impact cratering models. These case studies yield immediate insights into planet formation and evolutionary processes. They also highlight synergies between the methods invented here and forthcoming facilities, including: Artemis Moon exploration initiatives, Venus atmospheric probes, the Vera Rubin Observatory, and high-resolution spectrographs on thirty-meter class telescopes. These methods have near-term potential to answer some of the most pressing questions in planetary science. Long-term, they establish the precedent for new types of planetary forensics.
Recommended Citation
Cabot, Samuel, "High-Resolution Planetary Forensics" (2023). Yale Graduate School of Arts and Sciences Dissertations. 1011.
https://elischolar.library.yale.edu/gsas_dissertations/1011
