Sky

"The sky (or celestial dome) is everything that lies above the surface of the Earth, including the atmosphere and outer space.

In the field of astronomy, the sky is also called the celestial sphere. This is an abstract sphere, centred on the earth, on which the Sun, stars, planets, and the Moon appear to be traveling. The celestial sphere is conventionally divided into designated areas called constellations. Usually, the term sky is used informally as the point of view from the Earth´s surface; however, the meaning and usage can vary. An observer on the surface of the earth can see a small part of the sky, which appears to be a dome, also known as the sky bowl, flatter during the day than at night. In some cases, such as in discussing the weather, the sky refers to only the lower, more dense portions of the atmosphere." - (en.wikipedia.org 08.05.2020)