Mars southern mantle found to be up to 400°C hotter than north

An international research team led by the University of Arizona and the California Institute of Technology (Caltech) has discovered a significant temperature discrepancy within the interior of Mars. By re-analyzing decades of gravity data from the Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter missions, scientists determined that the mantle in the southern hemisphere is between 200 and 400 degrees Celsius hotter than in the north.

This thermal imbalance suggests that parts of the southern mantle may be partially melted. Researchers indicate that this finding provides direct geodynamic evidence regarding the planet’s magnetic heritage and its potentially moist geological past. The temperature difference could explain intense magnetic field variations in the south and seismic wave movements previously detected by NASA’s InSight lander.

Lead author Dr. Alexander Berne noted that while planetary interiors are often assumed to be symmetrically balanced, these findings demonstrate that internal dynamics are more complex. The heat source responsible for this disparity may have resulted from a massive meteorite impact or the presence of thick geological structures that trapped heat over time. Understanding this asymmetry is considered critical to uncovering the evolution of liquid water on the Martian surface.