A 400-Degree Mystery Deep Inside Mars

Scientists have discovered a vast thermal imbalance deep inside Mars, revealing that the planet's southern interior is about 200 to 400 degrees Celsius warmer than the northern half and possibly partially molten. Published on August 27, 2026, in the journal Nature, the research was led by Caltech alumnus Alexander Berne and utilized decades of gravity data from three spacecraft missions to perform tidal tomography. The research team found that Mars is thermally asymmetric below the surface, mirroring its well-known surface dichotomy of high southern terrain and low northern plains. This significant temperature difference helps explain several previously mysterious phenomena, including unusual magnetic signatures in southern iron-rich minerals and seismic wave behavior recorded by NASA's InSight mission. The underlying cause of this massive thermal anomaly remains uncertain, with potential explanations pointing to a giant impact releasing heat from the north, spontaneous mantle convection in the south, or thick geological insulating structures trapping excess heat. Resolving this mystery will provide critical insights into Mars's geological evolution, past hydrology, and ancient potential for supporting life. Researchers and space agencies can leverage these findings to design future planetary exploration missions and better understand the internal dynamics of rocky planets. Understanding the planetary interior serves as a crucial blueprint for deciphering how planetary bodies form, evolve, and retain conditions necessary for water distribution and habitability.