The Skies Above
The sky is the part of the atmosphere or of outer space visible from the surface of any astronomical objects . It is difficult to define precisely for several reasons. During daylight the sky of Earth has the appearance of a deep blue surface, but this is the result of the air scattering sunlight. The sky is sometimes defined as the denser gaseous zone of a planet atmosphere . At night the sky has the appearance of a black surface or region scattered with stars.
