Bright planet Jupiter in the night sky on this clear and cold evening. In the foreground is a birch with lava in different colors as I have used UV light to create fluorescence. Lichens on birch are usually harmless, superficial organisms that use the bark as a base without damaging the tree, often a sign of clean air. Common species include blue lichen and various crust lichens. Lichens do not penetrate the bark, do not cause rot and can benefit biodiversity by offering food to insects. The bright night sky is due to light pollution, caused by excessive or misdirected artificial night lighting, disrupting ecosystems, disrupting the circadian rhythm of humans and animals and obscuring the starry sky. It is a rapidly increasing environmental problem that negatively affects biodiversity, insect and bird migration patterns, and can be counteracted by targeted, warm white lighting, motion sensors and timers
