Mars's southern hemisphere runs 200 to 400 degrees Celsius hotter underground than the north, a new Nature study finds
A Nature study led by Caltech's Alexander Berne finds Mars's southern mantle is 200 to 400 degrees Celsius hotter than the north, and partially molten. Researchers used 16 years of gravity data from three NASA orbiters to map the planet's interior for the first time this way.
A new study published in Nature finds that Mars's southern hemisphere is running 200 to 400 degrees Celsius hotter underground than the north, and is partially molten. Led by Caltech alumnus Alexander Berne, now at the University of Arizona, the team used a technique called tidal tomography, analyzing 16 years of gravity data from three NASA orbiters (Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter) to reconstruct the planet's interior. The heat asymmetry lines up with the Martian dichotomy, the long-known divide between the mountainous south and flat north, and may help explain magnetic anomalies in southern rocks. Researchers still do not know exactly what is driving the heat; leading hypotheses include an ancient impact, ongoing mantle convection, or thick crust trapping heat for billions of years.