There was a ring around the moon last night. It was really magical. Cambridge is very badly lit. This can make cycling rather more exciting than it is perhaps meant to be, as pedestrians loom out startlingly from the surrounding murk, but it does have the benefit of allowing us to see the night sky.
It is lovely to be able to see the stars while cycling across my local park, and better still to be able to step out of my front door and see a bright moon, a little smudged by mist, with a great glowing ring around it.
I gather that it is an effect caused by ice crystals in the upper atmosphere. That may explain it, but it does not contain it somehow. It was weirdly moving. I stood for some time in the middle of the road just gazing up at it. Tap 'ring around the moon' into Google images. There are lots of photos. It will give you a little glimpse of what it looked like.
But it won't give you the magic.