[P-PS08] Lunar Science and Exploration

[PPS08-13] Recent Advances in Understanding the Lunar Dynamo: Insights from Paleomagnetic and Spacecraft Studies

★Invited Papers

*Masahiko Sato¹ (1.Tokyo University of Science)

Keywords:Lunar dynamo, Paleomagnetic study, Magnetic anomaly

Dynamo magnetic fields of terrestrial planets are generated by the convection of electrically conductive liquid metal within planetary cores. These dynamo fields evolve to reflect the dynamic states of planetary interiors. Moreover, the characteristics of the dynamo fields may play a significant role in controlling the surface environment of planets through electromagnetic interactions and other processes with the solar wind. Therefore, understanding the evolution of dynamo fields is crucial for constraining the broader evolution of planetary systems. The evolution of the lunar dynamo has been a topic of debate since the Apollo era. The existence of a lunar core dynamo was initially inferred from the paleomagnetic studies of Apollo samples (e.g., Cisowski & Fuller, 1986; Runcorn, 1996), and later confirmed by globally distributed magnetic anomalies observed by spacecraft such as Lunar Prospector and Kaguya (e.g., Tsunakawa et al., 2009). Paleomagnetic studies of Apollo samples, using modern paleointensity techniques—mainly the non-thermal method—suggested that the lunar dynamo may have persisted until 2–1 billion years ago (e.g., Mighani et al., 2020, and references therein). However, recent studies employing thermal treatments have challenged this, indicating that the Moon did not maintain a long-lived core dynamo (Tarduno et al., 2021). These differences in paleointensity, arising from methodological variations, have been further explored in subsequent studies (e.g., Jung et al., 2024; Zhou et al., 2024), intensifying the debate surrounding the lunar dynamo. In this review, I focus on recently reported paleofield data, particularly from the past decade. This includes paleomagnetic studies of Apollo samples (e.g., Tarduno et al., 2021; Jung et al., 2024; Zhou et al., 2024), paleomagnetic studies of Chang’e samples (e.g., Cai et al., 2025a, 2025b), and spacecraft-based studies of crustal remanences (e.g., Yang & Wieczorek, 2024). I will compare these data with particular attention to the differences in research methods.