A new study may have solved a long-standing mystery about the Moon's magnetism : Why do lunar rocks brought back by the Apollo missions show evidence of an intense magnetic field sometimes rivaling or exceeding that of Earth today? Considering the Moon is much smaller than our planet, and doesn't have the same internal energy and core dynamics that power Earth's magnetic field, it's surprising that these 3.5 billion-year-old rock samples have such strong magnetic signatures. In this new