New research indicates that Mars once hosted extensive underground rivers of magma beneath its crust, a discovery that could have significant implications for the planet’s past habitability. Scientists at the University of Oxford analyzed seismic data collected by NASA’s InSight lander, focusing on signals generated by meteorite impacts and quakes on Mars.

The team examined a previously unexplained seismic boundary located roughly 15 miles (24 kilometers) below the Martian surface. Their analysis, published in the journal Nature Astronomy, suggests that this boundary represents molten rock pools beneath the crust rather than simple isolated magma chambers, as had been previously assumed.

This interpretation points to a more intricate volcanic plumbing system on Mars than previously understood. Such a system may have contributed to a chemically varied crust capable of supporting key geological and atmospheric processes. These processes potentially included the generation of an atmosphere and even oceans, as well as climate regulation mechanisms traditionally associated only with planets exhibiting plate tectonics.

The presence of magma rivers beneath Mars challenges prior assessments that deemed the planet geologically and atmospherically static in a way that was unlikely to support life. Researchers propose that the complexity of Mars’s underground magma activity could have maintained conditions conducive to habitability, widening the spectrum of planets considered capable of fostering life.

Additionally, this finding prompts a reevaluation of other rocky planets previously regarded as uninhabitable due to the absence of plate tectonics. The study suggests that habitable environments may arise on planets with alternative geodynamic processes, emphasizing the need for further investigation into planetary interiors beyond Earth-like tectonic activity.