Fig. 5
From: Mars core structure—concise review and anticipated insights from InSight
Crystallization process of Mars’ core. Contours show pressure (left scale) and radius (right scale) where crystallization takes place along an adiabat extending from the CMB (horizontal gray line, labeled with T CMB). Dotted lines show Fe crystallization conditions, whereas dashed lines show Fe 3−x S 2 crystallization conditions. Gray box shows pressure/radius range of the core, and the anticipated compositional range of the core; range of radii of solid inner core crystallized from the liquid of 15 wt% S (vertical line) indicated by italic labels within the box. The dashed adiabatic temperature contours show that the core will grow rapidly with small changes in CMB temperature. The dotted Fe crystallization contours show that an iron ‘snow’ will form at the top of the core at temperatures below ∼1575 K. The range of inner core radii arises from alternative compositions of the solid core: Fe 3 S 2 or Fe 3S