000008204 001__ 8204
000008204 005__ 20261014151421.0
000008204 0247_ $$2DOI$$a10.1029/2025JE009368
000008204 037__ $$aSCART-2026-0159
000008204 100__ $$aDunnigan, Abigail H.
000008204 245__ $$aInterior Models of Mercury and Conditions for Iron Snow Formation in a Fe-S-Si Core
000008204 260__ $$c2026
000008204 520__ $$aMercury's unique interior structure and magnetic field generation remain to be fully understood. We construct models to further constrain Mercury's interior and test the hypothesis that iron snow within the liquid core drives the dynamo. We build upon previous models by incorporating an updated iron-sulfur-silicon (Fe-S-Si) core alloy composition and use a Monte Carlo approach to explore the parameter space consistent with geodetic and geophysical constraints. A high normalized moment of inertia (MoI) of 0.346 ±0.014, in combination with thermal and geochemical constraints, favors models with an Earth-like mantle density of  ∼3300 kg/m3, an inner core  ≤1050 km in radius, and a core silicon content of at least 6 wt%. In contrast, a lower value of MoI  =0.333 ±0.005favors models with lower mantle densities of  ∼3100 kg/m3, an inner core radius in the range of 850–1,450 km, and a core silicon content less than 8 wt%. We also show that the formation of iron snow requires a sulfur concentration greater than  ∼4 wt%. However, the expected geochemistry of the core restricts the sulfur content to less than 2 wt%. This inconsistency suggests the absence of snow layers in Mercury's present-day core and that its dynamo is not driven by sulfur-induced iron crystallization.
000008204 536__ $$a3PRODPLANINT/$$c3PRODPLANINT/$$f3PRODPLANINT
000008204 594__ $$aNO
000008204 700__ $$aLiu, Dunyu
000008204 700__ $$aSteinbrügge, Gregor B. 
000008204 700__ $$aRivoldini, Attilio
000008204 700__ $$aDumberry, Mathieu
000008204 700__ $$aCao, Hao
000008204 700__ $$aSoderlund, Krista M.
000008204 773__ $$n4$$pJournal of Geophysical Research: Planets$$v131$$y2026
000008204 8560_ $$fattilio.rivoldini@ksb-orb.be
000008204 8564_ $$s2184818$$uhttps://publi2-as.oma.be/record/8204/files/Dunnigan2026aa00.pdf
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000008204 905__ $$apublished in
000008204 980__ $$aREFERD