Moon's magnetic field shows brief strong spikes, Apollo rock study suggests.

Researchers re-examined Apollo lunar samples and report that titanium-rich rocks preserve evidence of brief, intense magnetic spikes three to four billion years ago; future Artemis samples from the south pole are expected to provide further information.

Lunar rocks brought back by Apollo missions are being re-evaluated and offer a new perspective on the moon's ancient magnetic history. A team at the University of Oxford analyzed earlier measurements and reports that the moon experienced short-lived but strong magnetic spikes billions of years ago. The study appears in Nature Geoscience and links those spikes to melting of titanium-rich material deep within the moon. NASA's Artemis program and planned south-pole samples are noted as a future source of additional evidence. Key findings: - The study re-analyzed measurements from Apollo lunar samples and is published in Nature Geoscience. - High titanium levels in rocks from Apollo 11 and Apollo 17 correspond with preserved traces of strong magnetic activity. - Researchers report magnetic spikes occurring three to four billion years ago that lasted no more than about 5,000 years and possibly as briefly as a few decades. - The team links the spikes to melting of titanium-rich rocks deep inside the moon, according to lead author Claire Nichols. - The Apollo samples came from similar low-latitude lava plains and may not represent the whole moon; Artemis missions plan to collect samples near the south pole for further study. Summary: The researchers conclude that intense, intermittent magnetic events recorded in Apollo rocks can account for earlier interpretations of a long-lived lunar field. Future Artemis missions aim to return samples from different regions of the moon, which could clarify how representative the Apollo material is, and Artemis II is scheduled as a crewed test flight around the moon after recent vehicle repairs.