Aurora by mica.mala 作者： mica.mala

An aurora is usually observed at night and typically occurs in the ionosphere. It is also referred to as a polar aurora or polar lights. These phenomena are commonly visible between 60 and 72 degrees north and south latitudes, which place them in a ring just within the Arctic and Antarctic polar circles. Auroras do occur deeper inside the polar regions, but these are infrequent and often invisible to the naked eye. Landscape with mountains, lake, night sky, and snow.