In short, the findings suggest there are more metals like iron and titanium in the Moon's craters than we thought there were – and that might point to a rich store of metal material just under the lunar surface.

This new research posits that there's even more metal material lurking just below the lunar surface, which wouldn't make sense if it had spun off from the relatively metal-poor Earth crust.

Follow-up analysis using data from other instruments and spacecraft confirmed that the larger craters contained more metal, quite possibly because they dig deeper into the Moon's surface.

Further research is already underway to ascertain if this link between more metal and bigger craters also holds true on the Moon's southern hemisphere.