How strong was the moon's magnetic field? Old Apollo rocks shed new light

Old Apollo rocks are providing a fresh take on the moon's magnetic field.

The lunar magnetic field is currently weak or even nonexistent, but cranked up to superstrength for short snippets of time more than a billion years ago.

Scientists at the University of Oxford in England reported the findings Wednesday after identifying the short spikes in high magnetic field strength through the moon rocks' titanium content.

Their study challenges the longtime belief that the moon's magnetic field remained strong for long stretches of time.

The researchers say rocks collected by NASA's future Artemis astronauts should yield even more clues.