NASA’s InSight mission to Mars helped scientists determine the internal structure of Mars, including the size and composition of its core, and provided general clues about its turbulent formation.

But the results of a new paper titled “Geophysical Evidence for an Enriched Molten Silicate Layer Above the Martian Core” published in the journal Nature, this may lead to reanalysis of the data. An international research team has discovered the existence of a molten silicate layer covering the metallic core of Mars; This provided insight into how Mars formed, evolved, and became the barren planet it is today.

The team’s paper, published on October 25, 2023, details the use of seismic data to locate and describe a thin layer of molten silicate (the rock-forming minerals that make up the crust and mantle of Mars and Earth) located between the Martian mantle and core. . With the discovery of this molten layer, researchers determined that Mars’ core is denser and smaller than previous estimates; this is a result more consistent with other geophysical data and analysis of Martian meteorites.

Vedran Lekic, professor of geology at the University of Maryland and co-author of the paper, likened the molten layer to a “warming blanket” covering the core of Mars.

“The blanket not only insulates the heat from the core and prevents the core from cooling, but also concentrates radioactive elements whose decay produces heat,” Lekic said. said. “And when this happens, the core will likely not be able to generate convective motions that would create a magnetic field, which could explain why Mars does not currently have an active magnetic field around it.”

Without a functional protective magnetic field around it, a terrestrial planet like Mars would be extremely vulnerable to harsh solar winds and would lose all water on its surface, making it unable to support life. Lekich added that this difference between Earth and Mars can be explained by differences in the internal structure of the two planets and different paths of planetary evolution.

“The thermal coverage of Mars’ metallic core by a layer of liquid at the base of the mantle means that external sources were required to generate the magnetic field recorded in the Martian crust during the first 500-800 million years of Mars’ evolution.” said the researcher. The lead author of the paper is Henri Samuel, a scientist at the French National Center for Scientific Research.

“These sources could be energetic shocks or core motion caused by gravitational interactions with older moons that have since disappeared.”

The team’s findings support theories that Mars was once a molten magma ocean that later crystallized to form a layer of iron- and radioactive-rich silicate melt at the base of the Martian mantle. Heat released from radioactive elements can significantly alter the Red Planet’s thermal evolution and cooling history.

“If these layers become widespread, they could have very serious consequences for the rest of the planet,” Lekic said. “Their existence could help us understand whether magnetic fields can be created and sustained, how planets cool over time, and how their internal dynamics change over time.”

NASA’s InSight mission officially ended in December 2022 after collecting data about Mars for more than four years, but analysis of observations continues. Samuel, Lekich and their co-authors are among the latest researchers to rethink previous models of Mars by using seismology to confirm the planet’s structure and turbulent past.

“This new discovery of the molten layer is just one example of how we continue to learn new things from the completed InSight mission,” Lekic said. “We hope that the information we collect about planetary evolution from seismic data will pave the way for future missions to celestial bodies such as the Moon and other planets such as Venus.”