The IndyMag project goal is to better understand the generation of magnetic fields in the rocky bodies of the solar system and beyond, combining models of the long term evolution of planetary interiors and planetary cores (how they evolve, how they crystallize), and observations of evidence of magnetic fields on such bodies.
The innermost planets in the Solar System are rocky. To first order their composition is similar to the Earth’s one, with an iron core, a silicate mantle and a surrounding crust. Their internal dynamics, in the core and mantle, present a large diversity of features, and this work is interested in the main product of the core dynamics: the magnetic field. Amongst the solar system planets, only Venus shows no sign of a past or present magnetic field. Other rocky bodies present evidence of present (the Earth, Mercury) or past (Mars, the Moon) magnetic fields, with various time and spatial variability. This diversity is poorly understood, and often planets are studied in separate studies.
The goal of the IndyMag project is to (i) model quantitative thermal and compositional evolution of rocky bodies’ cores, including variations in size and compositions and to (ii) generate synthetic observables of the time evolution and structure of the magnetic field of telluric bodies, to be compared to existing observations and models.
We showed that the thermal and chemical evolution of a planetary core is controlled primarily by its crystallization. We modeled the crystallization through two complementary approach: study of the effect of the crystallization on the solid fraction (Lasbleis et al. 2020, Geoph. Res. Lett.) and model of the thermal and compositional evolution of the outer core for various planetary properties (Bonati et al, 2021)
