Solved: Apollo samples show Moon had mostly weak field with brief super-strong pulses
Feb 27th 2026
New analysis of Apollo Moon rocks shows both sides of a long debate were right: the Moon was mostly weakly magnetised but produced very short, very strong magnetic pulses linked to titanium-rich volcanism and sampling bias in Apollo landing sites.
- New Nature Geoscience study from the University of Oxford finds the Moon had a weak magnetic field for most of its history but experienced very short, extremely strong pulses.
- Those rare strong pulses recorded in Apollo Mare basalts were stronger than Earths magnetic field.
- Strong magnetization correlates with high titanium in the basalts, with samples under 6 wt.% titanium all showing weak fields.
- Authors estimate the strong-field events lasted no more than 5,000 years and possibly as little as a few decades.
- The proposed mechanism is temporary melting of titanium-rich material at the core-mantle boundary that drove an intermittent dynamo.
- Apollo landing sites were biased toward titanium-rich Mare basalts, so returned samples overrepresent the rare strong-field events and upcoming Artemis missions can test the new prediction.