--Earths Moon Farside is rich in Thorium?--
description: The statement that the Moon's far side is rich in thorium is partially true but requires context. While thorium is primarily concentrated on the near side in the Procellarum KREEP Terrane (PKT), scientists have identified significant thorium anomalies on the far side that challenge our previous understanding of lunar composition. NASA (.gov) +1 Key Thorium Findings on the Far Side Compton-Belkovich Thorium Anomaly: This is a distinct, isolated "bull's-eye" of extremely high thorium concentration on the far side. Recent data from missions like the Lunar Reconnaissance Orbiter (LRO) suggests this area is a rare volcanic complex made of silica-rich granite, which is naturally enriched in radioactive elements like thorium and uranium. South Pole-Aitken (SPA) Basin : The far side's massive SPA basin shows moderate thorium enhancements. Researchers believe this thorium was excavated from the lower crust or upper mantle by the massive impact that formed the basin billions of years ago. New Evidence of Global Distribution: Data reported in March 2025 from private landers like Firefly Aerospace's Blue Ghost suggests that heat-producing elements like thorium may be spread more widely beneath the surface than previously modeled, potentially upending decades of thermal maps. USGS (.gov) +7 Comparison: Near Side vs. Far Side On a global scale, the near side remains the primary reservoir of thorium because of the KREEP (Potassium, Rare Earth Elements, and Phosphorus) layer. WashU +1 Feature Near Side (PKT) Far Side (General) Thorium Concentration High and widespread (up to ~18-30 ppm) Generally very low, with specific high "hotspots" Geological Origin Result of a "magma ocean" cooling and concentrating elements in one area Mostly low-thorium highlands, with isolated volcanic or impact-related anomalies While the far side is mostly composed of thorium-poor highlands, these specific anomalies are crucial for future energy production if humans establish a permanent presence, as thor…