There was a great huge ring around the moon last night, the crisp cold air reminded me of late fall nights in michigan, the air snapping around you, lights and stars bright white unwinking lights, the cold settling into your bones. The moon though, was bright and full, almost directly overhead, circled by a large unbroken ring of what looked like clouds. It was gorgeous.
What is it? Moon Halo
"If it's what I think you mean it's more common than you realise. Basically it's an optical illusion when you get very clear skies and fine ice particle in the upper atmosphere. What you get is the moon, a dark circle round it then a sky lit up with refracted moonlight."
It supposedly signifies bad weather on the way -- and boy did it pour today! Even had one stroke of lightning and subsequent thunder ( a rare rare event this time of year ). Looks like it is clearing up somewhat now, which is good given that I am going to be on a boat in the bay for the Sierra Club Christmas Party!
more info on moon rings