H2: Breakthrough on the Moon’s hemispheric dichotomy
A new study published in Nature Geoscience reports that the Moon’s mantle on the far side is colder than the mantle on the near side. The finding, based on lunar samples from Chang’e 6, offers crucial insights into the Moon’s hemispheric dichotomy—the striking contrast between the near and far sides in crust thickness, volcanic history, and internal heat. The research is a landmark in cross-disciplinary science, uniting China’s nuclear and space research communities to deepen our understanding of lunar evolution.
H2: How the discovery was made
Researchers analyzed lunar regolith and basalt samples brought back by the Chang’e 6 mission, the first attempt to retrieve materials from the Moon’s far side. They focused on the mineralogy of typical minerals such as clinopyroxene and plagioclase. By applying three different thermobarometers, they calculated crystallization temperatures and pressures. To reinforce their conclusions, the team built a petrological model to simulate the crystallization process of the Chang’e 6 samples. The independent methods converged on a consistent conclusion: the crystallization temperature of the far side samples is about 1,100 C, roughly 100 C cooler than near-side basalt. This temperature offset translates into a similar gap in the potential temperatures of the mantle beneath the far side.
H3: What the data say about the lunar mantle
Using the chemical compositions of the samples and the constructed magma models, the scientists estimate that the lunar mantle beneath the far side is about 100 C cooler than its near-side counterpart. They also cross-validated these results with lunar remote-sensing data to assess regional-scale implications, ensuring that the observation is not just localized but part of a broader hemispheric pattern.
H2: Why this matters for lunar history
The study ties mantle temperature differences to crustal thickness and the distribution of heat-producing elements across the Moon. A cooler far-side mantle implies different thermal evolution pathways for the two hemispheres, contributing to the long-standing puzzle of the Moon’s global asymmetry. The results add a new layer of evidence about how internal temperature, crust formation, and volcanic activity interplayed in the Moon’s early history.
H3: Broader implications and future research
The finding not only advances our understanding of lunar geology but also informs planetary science more broadly. By clarifying how a body can develop persistent hemispheric asymmetries in heat and composition, scientists can better interpret data from other rocky bodies, including early Earth. Li Ziying, a principal researcher on the project, notes that studying satellite bodies like the Moon yields insights into Earth’s own evolution, highlighting the value of cross-disciplinary work between nuclear and planetary science.
H2: The Chang’e 6 milestone
Launched in May 2024 from Hainan’s Wenchang Space Launch Site, Chang’e 6 marked the world’s first mission to return samples from the Moon’s far side. After 53 days of precise maneuvers, the mission delivered 1,935.3 grams of samples. The success not only demonstrates China’s growing capabilities in deep-space exploration but also provides vital material for experiments that reshape our understanding of lunar interior dynamics.
H2: Looking ahead
Researchers emphasize that this is a data-rich step toward mapping the Moon’s interior. Ongoing analyses, combined with ongoing or future missions, will refine the temperature and composition profiles of both lunar hemispheres. As scientists continue to integrate petrology, geochemistry, and remote-sensing studies, the Moon’s enigmatic interior is likely to reveal more surprises about how its near and far sides diverged so markedly over billions of years.
