Long‐Lived Lunar Mare Volcanism Powered by Radiogenic and Tidal Heating

Abstract Recent advancements in lunar remote sensing and sample analysis have uncovered prolonged mare volcanic activity on the Moon, spanning from approximately 4 billion to 1.2 billion years ago, with notable eruptions as recent as 2 billion years ago. This extended volcanic activity challenges the traditional view that radiogenic heating alone, from the decay of uranium, thorium, and potassium, could sustain such prolonged thermal energy. This study examines the additional role of tidal heating due to the viscoelastic deformation of the Moon Earth's tidal forces. Using orbital dynamics and viscoelastic models, we calculated the tidal dissipation power and found it to be comparable to radiogenic heating. Our results suggest that the combination of tidal and radiogenic heating could have co‐driven mare volcanism until 2 billion years ago, providing a more comprehensive understanding of the Moon's thermochemical evolution and volcanic history. Our results also show the importance of the Andrade viscoelastic model since it can add a dissipation energy to the radiogenic energy to generate the young volcanism with the whole range of lunar viscosity. In contrast, the Maxwell viscoelastic model can only sustain heating for a time span long enough to produce the young volcanism with an extremely low mantle viscosity induced by a large‐scale partial melting.