Tosi, Nicola ; Lécaille, Manon ; Rivoldini, Attilio, ; Baumeister, Philipp ; Namur, Olivier ; Charlier, Bernard

Poster presented at 46th COSPAR Scientific Assembly 2026, Florence, Italy on 2026-09-04

Abstract: Mercury’s long-lived, weak magnetic field provides a key constraint on the planet’s interior evolution. Yet, substantial uncertainties remain in the thermophysical properties of Mercury’s Fe-Si-rich core alloy. In this work, we investigate how uncertainties in core material prop- erties influence coupled mantle–core evolution models constrained by (1) present-day crustal thickness, (2) the timing of global contraction, and (3) long-lived dynamo activity. Using a 1-D parameterized convection framework linked to a thermodynamically-consistent core evolution model, we adopt a reference interior structure that satisfies the planet’s mass and radius. We then systematically vary key core parameters within plausible uncertainty bounds, including melting temperature, entropy of fusion, and thermal conductivity. Rather than perturbing individual quantities arbitrarily, we propagate uncertainties from the underly- ing equations of state to preserve internal thermodynamic consistency, while allowing indepen- dent variation where experimental constraints remain weak. We discuss how these parameter variations limit our ability to precisely reconstruct Mercury’s thermo-chemical history and to discriminate between competing evolutionary scenarios.

Funding: 3PRODPLANINT/3PRODPLANINT/3PRODPLANINT