Microscopic magnetic-field imaging of a single lunar dust grain

The origin of lunar magnetic anomalies-whether remnants of an ancient core dynamo or impact-induced magnetizations-remains debated due to a critical observational gap linking microscopic magnetic carriers to macroscopic orbital measurements. Conventional measurements lack sufficient spatial resolution or vector information at the sub-particle scales, obscuring the detailed micromagnetic signatures of formative geological events. Here, we report the first microscopic magnetic imaging (MMI) of individual lunar dust grain returned by the Chang'e-5 mission using a custom-designed quantum-sensing-based high-resolution microscopy, which simultaneously satisfies optimized sensitivity at 2.09-3.39 µT·Hz^-1/2, spatial resolution of 2.2 µm and field of view at 1 × 1 mm². Leveraging this, we precisely resolve magnetic field distributions with individual carriers, revealing magnetization processes linked to potential geological events at the sub-particle level. Preliminary quantitative magnetic analyses across these heterogeneous rock types further elucidate the possible historical events occurring at the task sampling site. Our approach enables imaging-based analysis of the magnetism of a single lunar dust grain and offers direct magnetism insights into the historical events from a microscopic perspective.