Natural light beams illuminate the night sky in Karamay, northwest China's Xinjiang Uygur Autonomous Region. (China News Service/Min Yong)

"Light pillars" are a rare optical illusion caused by falling ice crystals that reflect sources of light on the ground.

Natural light beams illuminate the night sky in Karamay, northwest China's Xinjiang Uygur Autonomous Region. (China News Service/Min Yong)

Natural light beams illuminate the night sky in Karamay, northwest China's Xinjiang Uygur Autonomous Region. (China News Service/Min Yong)