On August 3, a rare full circle rainbow appeared above the mountains in Shenzhen, South China’s Guangdong Province.
When sunlight and raindrops combine to make a rainbow, they can make a whole circle of light in the sky. However, it is a rare sight because sky conditions have to be just right, and even if they are, the bottom part of a full-circle rainbow is usually blocked by the horizon. That’s why we usually see rainbows not as circles, but as arcs across the sky.
(Compiled by Sun Shulang)
原文地址：http://en.people.cn/n3/2022/0818/c90000-10136783.html