NASA scientists have finally answered a long-standing question about why the Moon’s near side and far side are so different. Using data from the GRAIL mission, researchers developed a detailed gravity model revealing key differences in internal structure. The study, published in Nature, shows the near side has a hotter, more active mantle, likely due to ancient volcanic activity.

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• GRAIL data used to map Moon’s internal gravity variations
• Earth’s gravity causes Moon’s surface to flex (tidal deformation)
• Near side flexes more—points to internal structural difference
• Near side’s mantle is 100–200°C hotter than far side
• Heat linked to radioactive elements like thorium, titanium
• Near side shaped by ancient volcanic activity and dark lava plains
• Far side is colder, rugged, and full of craters
• Study suggests volcanism redistributed heat-producing elements
• Confirms long-standing theories of near side’s unique geology
• Moon key to Earth’s tides and rotational stability