Senior Project Advisor

Asmaa Boujibar

Document Type


Publication Date

Spring 2023


Planetary science, exoplanets, geophysics, geochemistry, interdisciplinary science


Internal heating in terrestrial planets is a fundamental physical process controlling the internal structure of a planet, mantle convection, volcanic activity, and the generation of magnetic fields. Internal heating results from various processes including radioactive decay and accretional energy, as well as additional irradiation and tidal heating in planets with short orbital periods. The largest long-term heat source for terrestrial planets is radioactive heating, especially from the decay of uranium (U), thorium (Th), and potassium (K) isotopes. K is a moderately volatile element, while U and Th are refractory elements; during planetary accretion volatiles are depleted relative to refractory elements, but the extent of depletion from planet to planet depends on many factors including orbital radii and the rate of accretion during formation. Therefore, the amount of K present in a given body has significant implications for its thermal evolution. Through combining compositional trends observed in chondrites and planets with models of planetary differentiation and thermal evolution, we examine the role volatile depletion plays in radioactive heat generation and estimate the resulting amount of heat production. Additionally, we carry out heat flow calculations using the Virtual Planet Simulator (VPlanet) to relate radioactive heating to planetary thermal structure and compare our results to bulk planet heat flow.






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