The moon: Magnetic field may have been disrupted by huge sinking rocks

There’s a new explanation for the moon’s former magnetic field, and it involves 60-kilometre-wide slabs of rock sinking through the lunar mantle


13 January 2022

The moon

The moon once had a relatively strong magnetic field


Moon rocks collected by the Apollo missions sparked a mystery because they showed signs of having formed under a magnetic field as strong as Earth’s, but it was unclear how a body as small as the moon could have created such a field. Now there is a potential solution.

Alexander Evans at Brown University in Rhode Island and Sonia Tikoo at Stanford University in California propose that giant rocks as large as 60 kilometres across once sank through the moon’s mantle …