there last night --which is why I took a picture. What causes them?
I found this explanation on another blog
A halo around the moon forms in the same way a halo around the sun forms. Light is refracted (or bent) by ice crystals, making a 22 degree halo. A 22 degree halo is the most common. See the diagram below to better understand how the light is refracted and where the 22 degree angle comes from.
Weather folklore says that a halo around the sun or moon means bad weather is on the way. I've also heard the number of stars inside the halo indicates the number of days before the bad weather will arrive.