Revisiting Modeling Mercury’s Interior Structure with Constraints from Magnetics

NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission provided many new insights into the formation and evolution of the enigmatic innermost planet, yet it also opened new lines of investigation. Of particular interest for this work are Mercury’s interior structure and the existence of an intrinsic magnetic field that is generated by convection in its fluid core (dynamo). Modeling Mercury’s interior structure has resulted in tight bounds on the size of its liquid core, yet questions remain, for example, concerning the existence of a possible inner core and the state of Mercury’s mantle. Most of the Mercury dynamo models employ complicated structures, such as a stably stratified outer portion of the core, to account for the observed weak field. Although a recent analysis found that a thermally stable layer formed in all their successful evolution models of Mercury’s interior (constrained by crustal thickness, contraction, and energy considerations for the possibility of the existence of a dynamo), this was only the case for a very limited number of