Second place in the 2021 IAU OAE Astrophotography Contest, category Light pollution. This composite image taken in Slovakia in 2020 illustrates the effect due to artificial illumination of light polluted areas. The higher the level of light pollution, the less we can observe in the sky, notice how the number of stars visible even to a sensitive digital camera decreases from right to left. Light pollution not only affects the visibility of objects in the night sky, but also significantly impacts ecosystems, negatively affecting many animals, such as migratory night birds, which may encounter difficulties to find the direction to where they should migrate to, or the sea turtles, which may be confused by the lights from coastal cities located near the beaches where they are supposed to spawn. Light pollution can also negatively impact some human health. Therefore, it is important to preserve the dark and quiet night sky for the benefit of the entire planet and all the diverse life it supports. Credit: Tomáš Slovinský/IAU OAE