Anomalies near crater suggest scattering of iron-rich debris
Iron-rich fragments from an ancient impact could explain puzzling magnetic fields measured in various places on the moon.
The magnetic anomalies are perplexing because unlike metallic minerals deposited by an asteroid, normal lunar rocks cannot record a magnetic field. “Those things are really non-magnetic,” says Ian Garrick-Bethell, a planetary scientist at the University of California, Santa Cruz. “The puzzle has been, how do you form these anomalies — how do you get anything that’s that magnetic?”