Mars interior revealed: hotter southern mantle beneath a cooler northern hemisphere

A gravity-based study using archival data from Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter with a tidal tomography method shows the southern mantle is 200–400°C warmer than the north, implying a hotter, potentially partially molten interior that helps explain Mars’ hemispheric surface dichotomy and seismic/magnetic clues. The exact cause—ancient giant impact vs crustal thickness differences—remains uncertain, and future gravity data could test the 3D interior model.