Moon's mighty magnetic field was a 5,000-year titanium blip

Scientists at the University of Oxford say they may have cracked the puzzle of the Moon's magnetic field and settled a debate that has raged since the Apollo missions returned with rock samples.

NASA astronauts brought back evidence suggesting the lunar magnetic field was strong for long periods of its history, at times even stronger than Earth's.

The findings created a puzzle, though. Scientists also considered the theory that the relatively small size of the Moon's core – around one-seventh of its radius – means it cannot create a strong field.

New research from Oxford's Department of Earth Sciences shows they are both right... kind of.

Led by associate professor Claire Nichols, the team analyzed the composition of a type of lunar rock known as the Mare basalts and found a new correlation between their titanium content and levels of magnetism.

Looking at the collected lunar samples, they ...