Recent findings from China's Chang'e-5 mission have shed new light on the Moon's magnetic history. Scientists from the Institute of Geology and Geophysics (IGG) under the Chinese Academy of Sciences (CAS) analyzed nine basalt samples collected from the Oceanus Procellarum region.
The study, featured as the cover story in Science Advances, reveals that approximately 2 billion years ago, the Moon possessed a weak yet active dynamo magnetic field. Measuring around 2 to 4 microteslas, this field was less than 10 percent of Earth's current magnetic strength.
Understanding the Moon's magnetic field is crucial for unraveling its internal structure, thermal history, and surface environment. The findings suggest that the lunar dynamo persisted into the Moon's midlife, driven by ongoing thermal convection in its deep interior. This convection likely provided the necessary heat for volcanic activity before the magnetic field eventually diminished.
In addition to the Chang'e-5 results, a recent study published in Nature based on samples from the Chang'e-6 mission indicates an unexpected resurgence in the Moon's magnetic field 2.8 billion years ago. These combined studies suggest that the Moon's magnetic field not only persisted longer than previously thought but also experienced fluctuations during its history.
The Chang'e-6 lunar probe, which returned in June 2023, brought back nearly 1,935 grams of samples from the Moon's far side, further enriching our understanding of the Moon's geological and magnetic evolution.
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Chang'e-5 samples reveal moon's weak but persistent magnetic field
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