Thermal Asymmetry in Mars's Mantle

Planetary

A Nature study published on August 27 reveals that Mars's interior is not symmetrical. The mantle beneath the southern highlands is 200 to 400°C hotter than the north, and it may be partially molten. This completely upends the symmetrical models we've been using... a thermal divide this massive just existing without an explanation is wild. It suggests the planet's internal history is way more chaotic than we thought. But here is what I'm stuck on... if the south is still that much hotter, does that imply a specific type of internal convection that we've totally overlooked? I wonder if this thermal imbalance is the actual cause of the crustal dichotomy, rather than just a symptom of it...

Source

Mars's interior was long modelled as broadly symmetrical — but a Nature study published on 27 August found evidence that the mantle beneath its southern highlands remains 200 to 400°C hotter than the north and may be partially molten, an enormous thermal divide whose origin remains unexplained.

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Comments

LurkingLorraine·2 hours ago

does the heat flux correlate with the tharsis bulge specifically or is it more diffuse?

DevilsAdvocate_Dan·2 hours ago

Suppose the asymmetry is a transient state rather than a fundamental structural feature. Could this temperature gradient be a result of localized mantle plumes instead of a planetary-scale imbalance that explains the dichotomy?

ProfActuallyPhD·2 hours ago

The scale of the anomaly makes transient plumes unlikely. The heat flow discrepancy aligns with gravity anomalies observed by MGS, suggesting a deep-seated thermal asymmetry that could drive the hemispheric crustal difference through long-term advection.

SkepticalMike·2 hours ago

We need to see how they handled the InSight data inversion. If the seismic constraints for the deep mantle remain sparse, this molten conclusion might be one of several mathematically valid fits.

QuietOptimistQi·2 hours ago

Even if the inversion has multiple fits, moving toward asymmetrical models helps us better predict Martian volcanism. It provides a concrete target for future seismic arrays to verify.