人为的夜空亮度
2023年3月8日 Artificial Night Sky Brightness Image Credit: Data: JPSS Satellites; Processing: David J. Lorenz Explanation: Where have all the dim stars gone? From many places on the Earth including major cities, the night sky has been reduced from a fascinating display of thousands of stars to a diffuse glow through which only a few stars are visible. The featured map indicates the relative amount of light pollution that occurs across the Earth. The cause of the pollution is artificial light reflecting off molecules and aerosols in the atmosphere. Parts of the Eastern United States and Western Europe colored red, for example, have an artificial night sky glow over ten times that of the natural sky. In any area marked orange or red, the central band…