Revision History

Data from China's Chang'e-4 lunar lander, analyzed over 31 lunar cycles, reveals a previously unknown zone of reduced galactic cosmic radiation between Earth and the Moon—a "cavity" where proton counts drop by roughly 20%, shaped by the far-reaching influence of Earth's magnetosphere. The discovery, published in Science Advances in March 2026, was independently corroborated by NASA's Lunar Reconnaissance Orbiter and could reshape radiation safety planning for crewed lunar missions.