New CE6 samples show the farside crust is more magnesium-rich, with higher peak Mg# in anorthosites, and Mg-suite rocks there have unusually low rare earth elements and lower Th/Sm ratios than Apollo-era materials, signaling different crustal evolution or KREEP distribution between hemispheres.

A proposed model suggests that after tidal locking, stronger tidal heating on the nearside created a temperature gradient that drove lateral convection in the lunar magma ocean, pushing magmas and early magnesium-rich crustal material toward the farside and thinning KREEP/IBC-rich layers on the nearside.

The finding is referenced in National Science Review (July 13, 2026) in Gu et al.’s study, ‘Lunar farside-nearside asymmetry formation during magma ocean solidification,’ with DOI 10.1093/nsr/nwag424.

This mechanism provides a self-consistent explanation for how a common mantle could produce two hemispheres with distinct crustal compositions and thicknesses, aligning with surface observations and CE6 laboratory analyses.

Geochemical data from CE6 anorthosites, Mg-suite rocks, and mare basalts indicate mantle cumulates beneath both hemispheres are broadly similar, implying the mantle itself was not strongly asymmetric.

Chang’e-6 analyses support the idea that uneven early heating drove magma from the nearside to the farside during the magma ocean phase after tidal locking, contributing to hemispheric differences.

The nearside is marked by extensive mare basalts and higher KREEP concentrations, while the farside shows ancient highlands, thicker crust, and fewer mare basalts, underscoring the crustal dichotomy.