Photo: Maxim Shemetov "Even...  ...A man walks through a tunnel formed by ice crystals from surrounding permafrost, outside...

Photo: brian s huff [Flickr]Did you see the ring a...  ...oon occurs when thin cirrus clouds, which contain ice crystals , refract the moonlight. A blog from the Goddard S...  ...light Center explains that "the shape of the ice crystals results in a focusing of the light into a ring. S...  ...in a focusing...