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?”
Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.