The internal structure of Mars' core is finally revealed

In the persistent quest to comprehend our cosmic neighborhood, scientists have reached a revelation concerning Mars, the enigmatic Red Planet. A recent study has illuminated details of a molten layer within Mars’ core, compelling scientists to rethink previous conceptions of its internal structure and geological history.

Subsurface sea of molten rock

This research, spearheaded by an international consortium, has identified a thin, previously undetected layer of molten silicates, essentially liquid rock, situated between Mars’ mantle and core.

These silicates are integral components of terrestrial planets, forming much of their crust and mantle. The revelation of their molten state within Mars is not just a geological curiosity. It demands a reevaluation of established models concerning the planet’s formation, evolution, and current state.

Rethinking Mars’ core

According to the team’s findings, the Red Planet’s core is denser and more compact than formerly believed. This discovery necessitates adjustments in correlated geophysical data and interpretations drawn from Martian meteorites.

Vedran Lekic, a professor of geology at the University of Maryland and the paper’s co-author, elucidates the role of this molten layer. He likened it to a “heating blanket” for Mars’ core.

This ‘blanket’ performs a dual function, both insulating the core, thus preventing heat loss, and concentrating radioactive elements that produce heat through their decay.

Mars’ core and habitability implications

One of the most consequential aspects of this discovery is its potential explanation for why Mars lacks a significant magnetic field. The heat preservation caused by the molten silicate layer may have rendered the core unable to generate the convective motions necessary for magnetic field creation, Lekic explains.

The absence of a protective magnetic field had profound implications for Mars. Without this shield, the planet became susceptible to solar winds. As a result, Mars eventually lost its surface water and, with it, any capability for sustaining life as we understand it.

Drawing parallels between Earth and its planetary cousin, Lekic highlights the divergent evolutionary paths reflected in their respective internal structures. The differences could account for the disparate geological developments and magnetic properties between the two worlds.

Henri Samuel, lead author and researcher at the French National Center for Scientific Research, adds depth to this discussion. He suggests that external forces might have been indispensable in generating Mars’ erstwhile magnetic field, evidenced in its crust. These forces could range from high-energy impacts to gravitational interactions with now-vanished Martian satellites.

Rewriting the Red Planet’s geological story

The team’s findings lend credence to the hypothesis that early Mars was enveloped by a molten ocean. This magma ocean would have crystallized over time, creating a silicate layer rich in iron and radioactive materials at the mantle’s base.

The thermal emissions from these materials would have significantly influenced Mars’ thermal evolution and cooling trajectory, setting it on its current barren course.

These insights not only highlight the molten layer’s importance, but also portend its broader implications for planetary science. “Understanding these layers can provide insights into planetary magnetic field generation, cooling processes, and internal dynamics across cosmic time,” Lekic asserts.

The InSight mission’s legacy continues

Though NASA’s InSight mission concluded in December 2022, its scientific contributions persist. The mission’s extensive data continue to fuel new hypotheses and discoveries about Martian geology. This is demonstrated by the work of Samuel, Lekic, and colleagues.

Their seismic investigations from InSight are validating. They enrich our knowledge of Mars’ structure and its chaotic past, shaping objectives and methodologies for future extraterrestrial missions.

Reflecting on the mission’s enduring influence, Lekic anticipates that their seismic research will inform future exploratory ventures to other celestial bodies. The data could potentially unlock further cosmic secrets hidden beneath the surfaces of the moon, Venus, or even more distant planets.

In shedding light on these buried Martian layers, scientists have not only reimagined the internal world of Mars but also underscored the dynamic, evolving nature of planetary science itself. With each discovery, we redraw the maps of our understanding, charting an ever-compelling journey through the mysteries of the cosmos.

The full study was published in the journal Nature.

—

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

—

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.