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Sky
The sky is an unobstructed view upward from the surface of the Earth. It includes the atmosphere of Earth, atmosphere and outer space. It may also be considered a place between the ground and outer space, thus distinct from outer space. In the field of astronomy, the sky is also called the celestial sphere. This is an abstract sphere, concentric objects, concentric to the Earth, on which the Sun, Moon, planets, and fixed stars, stars appear to be diurnal motion, drifting. The celestial sphere is conventionally divided into IAU designated constellations, designated areas called constellations. Usually, the term ''sky'' informally refers to a perspective 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 resembles a dome (sometimes called the ''sky bowl'') appearing flatter during the day than at night. In some cases, such as in discussing the weather, the sky refers to only the lower, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Night Sky
The night sky is the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon. Natural light sources in a night sky include moonlight, starlight, and airglow, depending on location and timing. Aurorae light up the skies above the polar circles. Occasionally, a large coronal mass ejection from the Sun or simply high levels of solar wind may extend the phenomenon toward the Equator. The night sky and studies of it have a historical place in both ancient and modern cultures. In the past, for instance, farmers have used the status 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 deities. The anciently developed belief of astrology is generally based on the belief that relationships between heavenly bodies infl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
