A crew of researchers on the Bayerisches Geoinstitut has carried out high-pressure-temperature laboratory experiments to find out the crystal construction and density of the iron-sulfide section within the Martian core.
Man et al. present that the high-pressure iron sulfide section with the system Fe4+xS3 has the next density than the liquid Martian core and {that a} Fe4+xS3 internal core would crystallize if temperatures fall under 1960 Ok on the middle of Mars. Picture credit score: NASA / JPL-Caltech / College of Maryland.
Much like Earth’s core, the core of Mars is predicted to be dominantly composed of molten iron metallic.
Nonetheless, it’s decrease in density, indicating that the Martian core should include a excessive abundance of further lighter components, similar to sulfur.
Beforehand it had been thought of that the temperature within the Martian core is probably going too excessive for a strong internal core to crystallize, however the opportunity of an iron-sulfide mineral forming the internal core had not been examined intimately.
“Observations from NASA’s InSight mission have revealed that the core of Mars is enriched in mild components, as its density seems to be considerably decrease than that of iron-nickel alloy,” mentioned Bayerisches Geoinstitut researcher Lianjie Man and colleagues.
“From cosmochemical views and geochemical concerns, candidate mild components within the Martian core embody sulfur, oxygen, carbon, and hydrogen.”
“Sulfur, specifically, is commonly highlighted as a possible main mild factor within the Martian core, primarily resulting from it being probably the most prevalent reasonably risky factor within the Photo voltaic Nebula, its ‘iron-loving’ conduct throughout core-mantle differentiation, and the truth that core formation on Mars was doubtless not a sufficiently lowering or high-temperature course of for silicon or oxygen to be main mild components.”
“Seismic and lander radio science knowledge from the InSight mission have confirmed that Mars has a liquid core, however the presence of a strong internal core can’t be at the moment excluded on geophysical grounds.”
“If additional geophysical observations had been to confirm the existence, measurement, and density of a Martian internal core, then mixed with the suitable mineral bodily interpretation, this would supply important constraints on the composition and temperature of the inside, in addition to the potential mechanisms that initiated and terminated the magnetic subject of early Mars.”
Of their research, the scientists carried out high-pressure-temperature lab experiments to find out the crystal construction and density of the iron-sulfide section in Mars’ core.
They counsel that, ought to temperatures on the middle of Mars fall under roughly 1,960 Kelvin — which is throughout the estimated vary for this space — the iron-sulfide section might start to crystallize and type a strong internal core.
Additional geophysical measurements could be wanted to substantiate the precise presence of a strong Martian internal core.
“Nonetheless, our work helps the potential for a strong internal Martian core at present, or within the close to future as soon as Mars has undergone additional cooling,” the authors mentioned.
Their paper was printed within the journal Nature Communications.
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L. Man et al. 2025. The construction and stability of Fe4+xS3 and its potential to type a Martian internal core. Nat Commun 16, 1710; doi: 10.1038/s41467-025-56220-2
