An international team of researchers has identified a striking feature deep beneath Mars: a molten silicate layer that sits just above the planet’s metallic core. This discovery refines our understanding of how Mars formed, how its interior evolved, and why its surface is so dry and inhospitable. The finding, reported in a leading scientific journal, marks a significant advance in modeling the planet’s interior and its explosive, sometimes violent, early history. NASA scientists played a key role in this breakthrough. By listening for Marsquakes and faint tremors from meteorite impacts, scientists can infer the planet’s internal structure. Seismic signals, together with measurements of the planet’s shape and gravity, help determine the size, composition, and state of the core. Taken together, the data indicate Mars has a layered interior that reflects a complex formation history characterized by vigorous activity in its youth. This layered picture fits a world that once hosted intense internal dynamics.
The presence of a dense molten silicate layer at the base of the mantle suggests Mars may host a smaller, denser core than previously thought. This adjustment aligns core properties with a broad set of geophysical observations, including gravity field data and the history of Mars’s magnetic activity. The molten silicate layer matches the idea of a global magma ocean in Mars’s early years. As that ocean crystallized, it left behind a distinct iron-rich zone at the bottom of the mantle. This zone continues to influence heat transfer today and drives mantle convection over geologic timescales. The new interior model helps explain how heat moved through Mars over billions of years and why the planet cooled in stages. The synthesis supports a narrative of early molten activity that gradually settled into the quiet, arid world seen today. Researchers anticipate new data to further test these ideas and refine the timeline of key events in Mars’s formative history.
Vedran Lekovic, a co-author and geologist from the University of Maryland, described the molten layer as a warming blanket enveloping the planet’s interior. That vivid image captures several roles: it helps retain core heat, slows the cooling of deeper regions, and concentrates heat-producing radioactive elements to sustain geological activity over long periods. The interpretation links Mars’s relentless early molten epoch to the calmer, present-day planet, while offering testable predictions about how heat sources are distributed beneath the surface. The study connects interior dynamics with the planet’s magnetic heritage, suggesting that the magnetic field observed in Mars’s past may have been shaped by this layered structure and heat distribution.
In a broader context, researchers are weaving these interior findings with evidence of ancient hydrology on Mars. Additional data hint that rivers and perhaps lakes existed long ago, shaping the early crust and surface features. The evolving interior model provides a coherent link between subterranean processes and surface geology, portraying Mars as a dynamic world where magma, heat, and water interacted during its formative chapters. Ongoing missions and planned investigations are expected to refine the timing and extent of these processes, enriching the story of how Mars shifted from a geologically active planet to the cold, arid world observed today. This integrated view offers a more robust, testable narrative about Mars’s interior and its surface evolution for scientists and space enthusiasts alike. The research aligns with a growing body of evidence that Mars once hosted flowing water and a more active crust, a theme that continues to guide mission planning and interpretation of surface features. — Attribution: NASA