There are ice crystals in the upper atmosphere where you are at, and it is refracting the light from the moon.
Think of it as a good thing, because you are seeing what are basically Moon rainbows. But because the light is reflected off of the Moon, and the refraction is many miles high, as opposed to basically ground level, you only see white in the ring.
This is a weather phenomenon, and has absolutely nothing to do with astronomy. It is called a lunar halo, is caused by ice crystals in the Earth's atmosphere, and usually indicates a change in the weather (for the worse).
we had one here tonight.. theres a rhyme: "ring around the moon, rain or snow is coming soon" it usually predicts bad weather but its caused by ice crystals in the atmosphere. and if u count how many stars there are inside the thats how many days till bad weather arrives.