Noctilucent clouds, also known as polar mesospheric clouds, form in a part of the atmosphere roughly 30 to 54 miles above the surface of our planet, making them the earths highest clouds. They are thought to be made of ice crystals that form on fine particles from meteors, can only form when temperatures are incredibly low, and when there’s water available to form ice crystals. Noctilucent clouds form when summertime wisps of water vapor rise up to the mesosphere, allowing water to crystallize around specks of meteor 'smoke'. Image credit: Kulik Bertrand ................................................................................ #science #art #nature #photography #education