Residents of Zhoushan, China, were alarmed when they recently spotted a blood-red sky. 

On May 8th, Chinese social media users Weibo and Sina published fragments of a crimson sky that went viral 

And many were curious to know what was going on 

Sky color changes as the camera moves over the sky 

Which seems brighter nearer the horizon while people stand and converse. 

From their homes, balconies, and streets, people documented the blood-red sky. 

More than 150 million people have seen the videos and images of the phenomena on China's Twitter-like social media 

Weibo and Sina, according to an article in Global Times.