Did the Moon, Earth's companion for billions of years, once sustained a global magnetic field? If so, when and by what mechanisms it ceased? The answers are critical to understanding the Moon's internal structure and thermal evolution history.
In recent years, orbital measurements have revealed spatially heterogeneous lunar magnetic anomalies, yet their origin remains debated: are they remnants of an ancient core dynamo, or magnetizations caused by localized events such as meteorite impacts? Resolving this question hinges on identifying the magnetic carriers within lunar regolith and their magnetic characteristics.
Conventional methods, however, face limitations. Orbital magnetometers lack sufficient spatial resolution (kilometer-scale), while macroscopic bulk rock-magnetic measurements (e.g., VSM) provide only volume-averaged information. Consequently, resolving magnetic distributions and origins at the single-particle or even sub-micron scale has become critical.
In a recent study published in Fundamental Research , Prof. Jiandong Feng's team at Zhejiang University, in collaboration with Prof. Jinhua Li's team at the Institute of Geology and Geophysics, Chinese Academy of Sciences, used a custom-designed magnetic imaging microscopy to conduct high-resolution magnetic imaging on Chang'e-5 lunar soils, realizing the direct observation of magnetic field distributions on single lunar regolith grains (Fig. 1).
The core instrument of this study is the NV quantum sensing based microscopy. This technique utilizes quantum defects in diamond as "super-probes" to achieve precise detection of weak magnetic fields. By optimizing the optical system and sensor design, the research team achieved the following advantages:
By observing basalt and breccia particles from Chang'e-5 lunar soils, the research team "saw" the specific carriers and origins of lunar particle's magnetism at the microscopic scale. The results indicate that lunar particle's magnetism is inherently heterogeneous and reflects multiple remanence acquisition processes:
Looking ahead, the teams plan to further optimize microscopy performance—improving spatial
resolution and sensitivity to access even smaller magnetic carriers—and to expand analyses to a broader suite of Chang'e-5 and Chang'e-6 returned samples. Systematic cross-sample comparisons are expected to provide stronger constraints on the spatiotemporal evolution of the lunar magnetic field, refining models of lunar interior evolution and supporting the continued advancement of deep-space exploration program.
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Contact the author:
Jiandong Feng, Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310058, China, jiandong.feng@zju.edu.cn ;
Jinhua Li, Key Laboratory of Deep Petroleum Intelligent Exploration and Development, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China, lijinhua@mail.iggcas.ac.cn
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Fundamental Research
Experimental study
Not applicable
Microscopic magnetic-field imaging of a single lunar dust grain
The authors declare that they have no conflicts of interest in this work.