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Gravity data reveals massive heat divide deep inside Mars

Researchers found the planet's southern interior is significantly warmer than the north, potentially resolving several Martian mysteries.

The short version

  • A study using tidal tomography has revealed that the interior beneath Mars's southern hemisphere is 200 to 400 degrees Celsius hotter than the northern interior, and may be partially molten.
  • The discovery could explain long-standing Martian mysteries, including unusual southern magnetic signatures and the rapid loss of seismic wave energy in the south detected by NASA's InSight mission.
  • While the temperature imbalance points to a deep geologic divide, the exact cause of this thermal anomaly remains unknown.

Key facts

  • The study, published August 27 in Nature, was led by Caltech alumnus and University of Arizona postdoctoral associate Alexander Berne.[ScienceDaily]
  • Researchers utilized tidal tomography to analyze gravity observations collected over decades by three spacecraft: Mars Global Surveyor, Mars Odyssey, and Mars Reconnaissance Orbiter.[ScienceDaily]
  • The findings show the southern interior of Mars is 200 to 400 degrees Celsius warmer than the northern interior.[ScienceDaily]
  • Understanding this temperature divide could provide insight into the hydrology of Mars, including the formation of ancient basins that may have held liquid water.[ScienceDaily]

What remains uncertain

  • The precise cause of the thermal anomaly is unknown, though scientists are considering three primary hypotheses: a massive northern impact that released heat, spontaneous convection in the southern mantle, or thick southern geological structures trapping heat.[ScienceDaily]

Sources