The term
night sky refers to the
sky as seen at
night. The term is usually associated with
astronomy, with reference to views of
celestial bodies such as
stars, the
Moon, and
planets that become visible on a clear night after the
Sun has set. Natural light sources in a night sky include
moonlight,
starlight, and
airglow, depending on location and timing. The Aurora Borealis and Aurora Australis light up the skies of the arctic and Antarctic Circle respectively. Occasionally, a large
Coronal Mass Ejection from the sun or simply high levels of solar wind extend the phenomenon toward the equator