The sky, also known as the celestial dome, commonly refers to everything that lies a certain distance above the surface of Earth, including the atmosphere and the rest of outer space. In the field of astronomy, the sky is also called the celestial sphere. This is an imaginary dome where the sun, stars, planets, and the moon are seen to be traveling. The celestial sphere is divided into regions called constellations. Usually, the term sky is used from the point of view of the Earth's surface. However, the exact meaning of the term can vary; in some cases, the sky is defined as only the denser portions of the atmosphere, for example.
During daylight, the sky appears to be blue because air scatters blue sunlight more than it scatters red. At night, the sky appears to be a mostly dark surface or region scattered with stars. During the day, the Sun can be seen in the sky, unless obscured by clouds. In the night sky (and to some extent during the day) the moon, planets and stars are visible in the sky. Some of the natural phenomena seen in the sky are clouds, rainbows, and aurorae. Lightning and precipitation can also be seen in the sky during storms. Birds, insects, aircraft, and kites are often considered to fly in the sky. As a result of human activities, smog during the day and light pollution during the night are often seen above large cities.
Famous quotes containing the word sky:
Warped in the weather, turned beldamish.
Then back came winter on me at a bound,
The pallid sky heaved with a moon-quake.”
—Robert Graves (18951985)
“When the sky is clear, carry an umbrella; though your stomach is full, carry provisions.”
“The sky breaks.
It sags and breathes upon my face.
in the presence of mine enemies, mine enemies
The world is full of enemies.
There is no safe place.”
—Anne Sexton (19281974)