Mars harbored vast Earth-like magma systems, study finds

A study published in Nature Astronomy on June 26 reveals that Mars once harbored vast, interconnected magmatic systems comparable to those found beneath Earth's surface — despite the Red Planet lacking the tectonic plates long considered a prerequisite for such geological complexity.phys+2

A Hidden Boundary Decoded

Researchers from the University of Oxford used seismic data from NASA's InSight mission to investigate a mysterious boundary roughly 24 kilometers beneath the Martian surface. By comparing hundreds of possible rock compositions against the seismic recordings using thermodynamic modeling and statistical techniques, they determined that only "ultramafic" rocks — rich in iron and magnesium but low in silica — matched the properties below the boundary, while "mafic" rocks with higher silica content lay above it.ox+1

The team concluded that this layered structure formed where molten rock pooled deep underground and gradually separated, leaving dense crystals at the base of the crust while lighter, more evolved melts rose upward. On Earth, similar processes occur beneath volcanic arcs and are tied to the formation of continents.phys

"We've traditionally assumed that volcanism on Mars was relatively simple compared to that on Earth," said lead author Dr. Tobermory Mackay-Champion, who conducted the research at Oxford and is now at the University of Bristol. "But this discovery suggests Mars could sustain large, long-lived systems where molten rock evolved and reprocessed itself throughout the entire crust."eurekalert+1

Rethinking What Planets Need for Habitability

The study suggests this buried layer may extend laterally for hundreds or even thousands of kilometers across Mars' northern hemisphere, pointing to a phenomenon known as "transcrustal magmatism" — previously thought to be unique to Earth.the-independent+1

Co-author Professor Jon Wade of Oxford's Department of Earth Sciences said the findings carry broad implications. "If Mars could develop this kind of complex crust without plate tectonics, then maybe the conditions needed for habitability could emerge on more planets than we realized, including those previously dismissed based on size or their apparent lack of tectonic activity."phys

Building on InSight's Legacy

The research draws on observations from NASA's InSight lander, which placed the first seismometer on Mars in 2018 and recorded marsquakes and meteoroid impacts until the mission ended in 2022. The data continue to yield discoveries about the planet's interior structure, including a 2025 finding of possible liquid water at the base of Mars' upper crust. The new study was conducted by researchers from Oxford's Departments of Earth Sciences and Statistics in collaboration with the University of Bristol.pmc.ncbi.nlm.nih+1