How the Moon Became Magnetized. (it has a molten core)

Astronaut Harrison Schmitt grabbed a magnetic rock from the Moon, and there were others it seems. Now researchers at the University of California have come up with an idea, the Moon may in fact still have a partially-liquid core.
I'm not too sure what is meant when they use the word partially, maybe that's just a term of accomodation. A molten core of some description in a large body tied to a solar system makes sense though, with all the gravitational pulling and pushing, friction has to be involved somewhere, and likely more pronouced to the centre of the body rather than the outskirts. I'm not sure either how that gels with the famous,"rings like a bell" which is observed when the Moon gets a hit, but then the Earth has the same observed quality in 'quakes. Have a look at the link anyway,

www.universetoday.com...-90829