Fragments of iron-rich ore from an ancient collision may be responsible for the strange magnetic fields measured in various places on the moon.
Normal lunar rocks are completely non-magnetic, so the puzzle for scientists has been to determine the source of the moon’s magnetic material. The new research links the magnetic anomalies to the South Pole-Aitken basin, the moon’s largest impact crater, suggesting that the impact which left the crater also deposited the magnetic material.
Read more at Institute of Earth Physics of Paris