Mars southern hemisphere contains massive thermal anomaly

Researchers have discovered a massive thermal anomaly within the interior of Mars, revealing that the planet is composed of two distinct halves. A study published in the journal Nature indicates that the mantle beneath the southern hemisphere is between 200 and 400 degrees Celsius warmer than the northern hemisphere, potentially remaining partially molten.

Lead author Alexander Berne, a researcher at the University of Arizona, and his team utilized archival data from three NASA spacecraft—the Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter—to identify the anomaly. By monitoring subtle changes in orbital velocities, the team applied a technique called ‘tidal tomography’ to reconstruct the planet’s gravitational field and internal structure.

This discovery provides a potential explanation for the stark dichotomy between the northern hemisphere’s flat lowlands and the southern hemisphere’s rugged, cratered highlands. The thermal asymmetry may also influence understanding of Mars’s ancient magnetic field, volcanic activity, and historical habitability.