Apollo rocks reveal brief lunar magnetism

LONDON, Feb. 26, 2026 — A new analysis of Apollo lunar rocks suggests the Moon’s magnetic field occasionally spiked to strengths stronger than Earth’s but only briefly, settling a decades-long debate, the University of Oxford said.

Researchers reexamined samples from the Apollo landing sites and concluded the intense fields were rare bursts rather than a long-lived dynamo, ScienceDaily reported.

Why Apollo rocks misled

Apollo missions landed on mare basalts in similar regions, leaving scientists with a rock record skewed toward high-titanium material that captured those intense magnetic episodes, Phys.org reported.

An Associated Press report said the most strongly magnetized Apollo 11 and Apollo 17 samples were also rich in titanium, reinforcing the sampling-bias explanation, according to CBC News.

Intermittent dynamo, brief spikes

In Nature Geoscience, the authors describe an intermittent high-intensity epoch between roughly 3.58 and 3.85 billion years ago, with short-lived surges amid generally weak fields.

The Oxford team estimates the spikes lasted no more than 5,000 years and possibly only decades, while the Moon’s magnetism stayed weak for most of its history, ScienceDaily said.

What Artemis samples could add

Future Artemis missions sampling the lunar south pole could provide a broader record of magnetism than Apollo’s equatorial sites, the AP report noted.

If high-titanium volcanism triggered brief dynamo episodes, the findings could explain how small planetary cores still produce magnetic surges, Phys.org said.

Researchers say expanding the sample set and comparing it with lunar swirl and crater magnetism should refine the timing of these bursts, the Oxford release said.

How we report: We select the day’s most important stories, confirm facts across multiple reputable sources, and avoid anonymous sourcing. Our goal is clear, balanced coverage you can trust—because transparency and verification matter for informed readers.