To best view a lunar halo, sky conditions must be clear with only a thin layer of cirrus clouds. If thicker clouds are present at lower levels, they'll obscure the halo effect. As moonlight shines ...

That bright, circular halo is a natural optical phenomenon ... sun halos form when high-altitude clouds — specifically cirrus or cirrostratus clouds — contain ice crystals that act like ...

Residents in the Kamloops area were treated to a halo around the sun on a blue-sky day in early March, and some shutterbugs ...