It refers to the sky what we see at the night. The term is usually associated with astronomy, it includes bodies such as stars, the Moon, and planets that become visible on a clear night after the Sun has set preferably without clouds. Natural light sources in a night sky consist of not only moonlight, star light, and airglow, but also satellites and comets depending on location and timing.
The studies of night sky runs history and it has taken a important place in modern science also. In the past, for instance, farmers have used the state of the night sky as a calendar to determine when to plant crops. Many cultures have drawn constellations between stars in the sky, using them in association with legends and mythology about their divinity.
People have a developed astrology based on the belief that heavenly bodies are influencing or affecting information and events about Earth and human. The scientific and systematic study of the night sky and bodies observed within it, meanwhile it takes place in the science of astronomy and also astrology.
