Scientists have identified another possible commonality between Earth and Mars: a solid inner core.
New research from the University of Bayreuth and the European Synchrotron Radiation Facility (ESRF) conducted here on Earth found that an iron and sulphur mixture mirroring the Red Planet’s inner core crystallized under high heat and pressure. This suggests that the deep interior of Mars could, in fact, be solid, too.
This research contradicts previous studies using Marsquake data from NASA’s InSight Mars Lander, which supported the belief that the Red Planet has a liquid core. Many geoscientists also argue that Mars’ molten center is too hot and consists of lighter elements like sulphur, making it less likely to solidify.
Using diamond anvil cells — a technique that uses two diamonds to squeeze material to create extreme pressures — and laser heating, the researchers subjected iron-sulfur samples to extreme conditions resembling the deep interior of Mars.
According to an ESRF statement, this, in turn, created a novel iron-sulfide crystal phase called Fe4+xS3.
Subsequent experiments showed that the iron-sulfide could crystallize from liquid even when subjected to lower temperatures within the estimated range of Mars’s core.
Therefore, if Mars’ deep interior were on the cooler side, then a solid core seems perfectly feasible, the researchers said in the statement.
Mars and Earth share many similarities, including geographic features like polar ice caps, volcanoes, and canyons. Similarities between Earth and Mars also include a roughly 24-hour day, an axial tilt that creates distinct seasons, weather patterns, and a rocky composition.
Having a solid core would be yet another characteristic that makes Mars one of the most Earth-like planets in our solar system.
While Mars is believed to have once been home to flowing rivers and lakes billions of years ago — much like Earth — the planet has become a cold, dry desert today.
Studying Mars’ internal structure is key to better understanding this evolution; however, further research is required to determine if the Red Planet’s core is solid or not.
The findings were published Feb. 25 in the journal Nature Communications.