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

The night sky refers to the sky as it is seen at night.