Alte Apollo-Gesteine ​​werfen vor langer Zeit neues Licht auf das Magnetfeld des Mondes | Ein intermittierender Dynamo im Zusammenhang mit Vulkanismus mit hohem Titangehalt auf dem Mond

Highlights from the news article:

>Lunar rocks collected by Apollo astronauts more than half a century ago are providing a fresh take on the moon’s mysterious magnetic field, scientists reported Wednesday.
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>The study by University of Oxford researchers in England suggests that while the moon’s magnetic field has been weak during most of its existence, it strengthened and even exceeded Earth’s magnetic activity during extremely brief periods 3 billion to 4 billion years ago. Their findings appear in the journal Nature Geoscience.
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>Magnetic fields help to shield against dangerous cosmic rays and, in the case of Earth, the sun’s harsh radiation as well.
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>The moon had “incredibly short spikes in high magnetic field strength” lasting no more than 5,000 years and possibly as short as a few decades, the result of melting titanium-rich rocks deep within the moon, said lead author Claire Nichols.
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>Scientists previously theorized that the lunar magnetic field remained strong for long stretches based on their analysis of rocks fetched by Apollo moonwalkers from 1969 through 1972. With Artemis astronauts exploring the moon’s south polar region instead of the low-latitude lava plains of Apollo days, the new samples should shed even more light on the moon’s ancient magnetism.
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>Nichols and her team pored over earlier measurements of the Apollo samples and found that high titanium levels corresponded with preserved traces of high magnetic activity. Rocks from the first and last moon landings — Apollo 11 and Apollo 17 — were loaded with titanium.
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>“We have found a missing link,” Nichols said in an email. Magnetic field activity can be “intermittently really strong and may fluctuate far more than we have traditionally thought.”

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Direct link to research:

[An intermittent dynamo linked to high-titanium volcanism on the Moon](https://www.nature.com/articles/s41561-026-01929-y)

Abstract:

>The history of the lunar magnetic field is a longstanding controversy. Many palaeomagnetic studies provide evidence for either a persistent, weak magnetic field or the lack of an intrinsic magnetic field between 1.020 and 3.580 billion years ago. However, for the period between 3.580 and 3.854 billion years ago, palaeomagnetic studies have recovered strong intrinsic fields (>40 µT) distributed among weak or null intensity measurements. Crustal magnetic anomalies from this period have also been interpreted as evidence for the presence of both strong and weak magnetic fields. Here we explore potential links between published palaeointensity, rock magnetic and geochemical data for lunar basalts. We find there is a statistically significant relationship only between recovered palaeointensity and the titanium content of lunar basalts. By modelling the heat flux across the core–mantle boundary, we suggest that there is a causal link between lunar dynamo generation and the eruption of high-titanium basalts. Such a link may result from the intermittent melting of ilmenite-bearing cumulates at the core–mantle boundary. The coincidence of these rare events probably reflects sampling bias near high-titanium basaltic terranes.