... Close inspection shows these strange columns of light occur over bright lights, and so likely involve falling ice crystals reflecting back these lights. ... The air was noted to be quite cold and indeed filled with small ice crystals, just the type known to create several awe-inspiring but well known sky phenomena such as light pillars , sun pillars , sun dogs , and moon halos . ... Publications with keywords: light - ice crystals . Publications with words: light - ice crystals . ...