Lunar rocks gathered by Apollo astronauts over 50 years ago are offering new insights into the moon’s enigmatic magnetic field, as per a recent report by scientists. Fresh samples anticipated to be collected during NASA’s Artemis program are expected to provide further information. The University of Oxford researchers in England have proposed in a study that the moon’s magnetic field, although generally feeble throughout its history, experienced periods of significant strength surpassing Earth’s magnetic activity briefly around three to four billion years ago. These findings were published in the journal Nature Geoscience.
Lead author Claire Nichols explained that the moon exhibited brief spikes in intense magnetic field strength lasting up to 5,000 years, possibly even just a few decades, due to the melting of titanium-rich rocks deep within the moon. Prior assumptions about prolonged strong magnetic fields on the moon were based on analysis of rocks brought back by Apollo missions from 1969 to 1972. With Artemis astronauts focusing on exploring the moon’s south polar region instead of the low-latitude lava plains visited during the Apollo missions, the new samples are anticipated to shed more light on the moon’s ancient magnetism.
Nichols and her team re-evaluated previous measurements of the Apollo samples and found that elevated titanium levels correlated with preserved evidence of high magnetic activity. Rocks from both the initial and final Apollo missions, Apollo 11 and Apollo 17, contained significant amounts of titanium. The researchers believe that the Apollo samples are not entirely representative of the moon’s composition since they originated from similar titanium-rich locations brought to the surface by volcanic eruptions.
Future Artemis missions aim to investigate ancient rocks near the moon’s south pole, where shaded craters are believed to harbor water ice. Nichols emphasized that comprehending the moon’s magnetic shield history is crucial for contemplating planetary habitability.