In just over a month, a blue sun appeared three times in Beijing on March 15, March 28, and April 21. This phenomenon has caused widespread concern, as such sights are typically only seen on Mars.
On March 15, 2022, media outlets reported that the weather in Beijing, China, was extremely unusual that day. Not only did the city experience the strongest sandstorm in a decade, resulting in six fatalities and over 80 people missing, but many also captured images of the blue sun.
The blue sun continuously appearing in China.
By April 21, 2022, the sandstorm struck Beijing once again, and once more, people reported seeing the blue sun.
From the videos and images circulating on the internet, the blue sun hung high in the sky, surrounded by a blue halo. The sky itself was also tinted blue, making the entire scene reminiscent of a sunset on Mars.
Experts believe this is due to the dusty weather in Beijing and surrounding areas, which altered the composition of airborne particles. Dust absorbs longer-wavelength red light, leaving shorter-wavelength blue light unaffected, resulting in a blue sun as perceived by our eyes.
This means that speculations that the blue sun is an omen of impending disaster are completely unfounded.
In addition to explaining the principle behind this phenomenon, experts also issued a warning: do not look directly at the blue sun. Although the light may appear weaker, the nature of sunlight remains unchanged. Human eyes are sensitive to light, and looking directly at the blue sun for an extended period can potentially harm your vision.
Image of a sunset on Mars showing a blue sun.
| Previously, scientists captured an image of a sunset on Mars showing the sun as blue. This is explained by Mars’ thin atmosphere, which is about 96% carbon dioxide, allowing it to absorb longer-wavelength light and leave behind shorter-wavelength blue light. Combined with the tiny particles remaining in Mars’ atmosphere, they can scatter blue light powerfully, with an intensity nearly ten times that of red light. Thus, when standing on Mars, one can see the sun as blue. |
