Why does the sky shine at night?

There are many reasons why the sky shines at night.

First of all, some luminous stars, including stars and quasars, will flicker with different brightness, which mainly depends on the luminous intensity of the stars and the distance from the earth. If there is smog in the air, or there are floating dust, sandstorm and other weather conditions, the night sky will be illuminated by the reflected light of floating dust in the air, making the sky look brighter. In addition, the light from the ground will enter the sky after being reflected by the ground, and then be diffusely reflected by the bottom of the clouds, which will also make the sky look brighter. Under certain conditions, such as high air humidity, fog or temperature drop, some water in the air condenses into fog, and fog droplets or haze particles can scatter ground light, further increasing the brightness of the sky.

In addition, celestial bodies close to the earth, such as Venus, Mars and other planets and the moon, will also reflect sunlight, especially during the full moon. Because the moon is closer to the earth, it looks bigger and reflects more sunlight, which makes the sky look brighter at night.

It should be noted that if the bright area of the sky is expanding and the brightness is getting stronger and stronger at night, it may be caused by astronomical phenomena such as fireballs. If it is accompanied by strong flashes and cracks, it is usually caused by meteorites falling into the atmosphere. In this case, it is recommended to contact a professional institution for investigation as soon as possible.

To sum up, there are many reasons why the sky glows at night, which may be natural phenomena or human factors. If you are curious about this phenomenon or need to know more about it, it is recommended to consult a professional or inquire about the latest relevant information.