Media release

From: Springer Nature

Planetary science: A potential Martian solid inner core

Geochemical evidence from laboratory experiments for a potential solid inner core at the centre of Mars is reported in Nature Communications.

Data from NASA’s InSight mission has revealed that Mars has a liquid core. Similar to Earth’s core, the core of Mars is expected to be dominantly composed of molten iron metal. However, it is lower in density, indicating that the Martian core must contain a high abundance of additional lighter elements, such as sulphur. Previously it had been considered that the temperature in the Martian core is likely too high for a solid inner core to crystallise but the possibility of an iron-sulphide mineral forming the inner core had not been examined in detail.

Lianjie Man and colleagues conducted high-pressure-temperature laboratory experiments to determine the crystal structure and density of the iron-sulphide phase in Mars’ core. The authors suggest that, should temperatures at the centre of Mars fall below approximately 1,960 Kelvin (which is within the estimated range for this area) the iron-sulphide phase could begin to crystallise and form a solid inner core. Further geophysical measurements would be needed to confirm the actual presence of a solid Martian inner core. However, the work presented in this study supports the potential for a solid inner Martian core today, or in the near future once Mars has undergone further cooling.