Mars may have a solid inner core

Mars has a liquid core, according to data from NASA's InSight mission, but the existence of another solid inner core cannot be ruled out, according to a study based on laboratory tests published by Nature Communications.

Like Earth, Mars' core is composed mostly of molten iron, but its lower density suggests it must contain an abundance of other, lighter elements, such as sulfur.

Research led by the University of Bayreuth (Germany) indicates that, until now, it was thought that the temperature of the Martian core was probably too high for it to crystallize into a solid inner core.

However, the possibility that iron sulphide mineral formed the inner core has not been examined in detail, notes the magazine, cited on Tuesday by the Efe agency.

The authors acknowledge that more geophysical measurements would be needed to confirm the actual presence of a solid inner core on Mars, but the study supports the possibility that it exists today or in the near future as the planet cools further.

The team performed high-pressure, high-temperature laboratory experiments to determine the crystal structure and density of the iron sulfide phase in the Martian core.

The research suggests that if temperatures in the Martian core drop below about 1,960 degrees Kelvin (which is within the estimated range for this region), the iron sulfide phase could begin to crystallize and form a solid inner core.

This week, Mars has been the subject of several scientific studies that have appeared in several journals. On Monday, PNAS published a study that reveals that about 3.6 billion years ago, there was an ocean with sunny sandy beaches and gentle waves.

The study, led by an international team, analyzed layers of rock in the Martian subsoil, which attest to the existence of a vast ocean north of Mars, using data collected by Zhurong, the Chinese rover that traveled 1.9 kilometers through Utopia Planitia between May 2021 and May 2022.

A second study of the red planet published in Nature Communications has provided an alternative explanation for why Mars is this color.

Research suggests that the water-rich iron mineral ferrihydrite is the cause of the reddish color of the dust covering Mars, and not hematite, as previously thought.