University of Arizona Lead Author Alexander Berne Nature Paper Southern Mantle Divergence Could Explain Ancient Magnetic Field Water Basins And Hemispheric Surface Differences Three Competing Hypotheses: Giant Impact, Random Convection, Southern Highland Crust Insulation Caltech’s Bagheri: Influenced Mars Hydrology Anomaly Opens Blueprint For Future Mission Design
According to Futurism/Nature, scientists have detected a striking “thermal asymmetry” buried deep beneath Mars’ southern hemisphere with the interior of the planet’s southern half measuring approximately 400 to 750 degrees Fahrenheit warmer than its northern counterpart, according to a new paper published in the journal Nature on August 29, 2026.
Lead author Alexander Berne, a planetary scientist at the University of Arizona, said the discovery challenges a standard assumption: “Scientists usually assume that the interiors of planetary bodies are generally spherically symmetric, but this is not necessarily true.” Using gravity data, the team mapped three-dimensional variations in Mars’ interior structure, revealing what they term a fundamental thermal anomaly between the two hemispheres, which already differ dramatically at the surface: the southern half is densely cratered and several miles higher, while the north is relatively smooth.
Three hypotheses are currently under consideration. The first is a giant impact that forced heat to escape the northern hemisphere. The second involves random convection currents in Mars’ ancient past. The third, supported by the paper, holds that the southern highlands’ thick crust has been insulating excess mantle heat for billions of years. Caltech’s Amirhossein Bagheri said the anomaly may have “influenced the hydrology of Mars, including the formation of basins that may have held water.”
Brown University’s Nick Wagner acknowledged the study adds evidence to an ongoing fundamental question but does not yet resolve it.
Mars has two faces. The inside explains something about why. Check out our previous coverage of science and space on The Trusted Times.
