A new study by the University of Oxford in the UK may have solved a longstanding mystery about the Moon's magnetism. Lunar rocks brought back by the Apollo missions show evidence of an intense magnetic field, sometimes exceeding that of Earth today. The study suggests that these strong magnetic signatures could be caused by sudden bursts of magnetism brought on by ancient geological processes long before the Apollo mission landed. The Apollo samples were found to have a sampling bias, suggesting they were more likely to represent rare events that lasted a few thousand years. The team also found a link between rocks with stronger magnetism and their higher titanium content. However, they acknowledge that their models are based on several assumptions and that more data will be needed to confirm these findings.