![](http://www.ecns.cn/hd/2024/03/08/2ce73f68d69148a78be17503a9163b31.jpg)
Natural light beams illuminate the night sky in Hulunbuir City, north China's Inner Mongolia Autonomous Region on March 6 morning. Known as “light pillars”, they are a rare optical illusion caused by falling ice crystals that reflect sources of light on the ground. (Photo: China News Service/Wang Ying)
![](http://www.ecns.cn/hd/2024/03/08/0552296cab83455d87a00a1d9a06e9df.jpg)
Natural light beams illuminate the night sky in Hulunbuir City, north China's Inner Mongolia Autonomous Region on March 6 morning. Known as “light pillars”, they are a rare optical illusion caused by falling ice crystals that reflect sources of light on the ground. (Photo: China News Service/Wang Ying)
![](http://www.ecns.cn/hd/2024/03/08/092145012e544c4ab4d263bb237968b3.jpg)
Natural light beams illuminate the night sky in Hulunbuir City, north China's Inner Mongolia Autonomous Region on March 6 morning. Known as “light pillars”, they are a rare optical illusion caused by falling ice crystals that reflect sources of light on the ground. (Photo: China News Service/Wang Ying)