The celestial sphere is the apparent sphere of the sky. The view in this figure is from the outside of the sphere. Because the Earth is at the center of the celestial sphere, however, our view is always of the inside of the sphere. The celestial equator and poles are the projections of the Earth's equator and axis of rotation out into space. The celestial poles are therefore located directly over the Earth's poles. (Universe5)

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One of 88 designated areas in the sky or the pattern of stars within it. Records show that,from antiquity, civilizations have given names to conspicuous patterns of bright stars. Each culture had its own way of dividing the sky into pictorial elements. Many of those in use today originated in Mesopotamia and were further developed by the Greeks. Ptolemy listed 48 in the second century AD and the rest have been added since about 1600. Some proposed constellations that have never found general acceptance appear on old star maps.
Originally, constellations were regarded simply as star patterns, but they gradually acquired usefulness as a way of specifying stars and their positions. As the science of astronomy developed, the lack of precise standard definitions for the constellations led to confusion in identifying fainter stars in more sparsely populated regions of the sky. This was resolved when, in 1930, there was international agreement among astronomers to define the boundaries of 88 constellations along lines of right ascension and declination.
Click here to see list of constellations. (Red shift 3)

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A band of hazy light circling the sky. It results from the combined light of vast numbers of stars in our own Galaxy. The term Milky Way is also used as a synonym for the Galaxy.
The band of light around the celestial sphere is the disc of the Galaxy viewed from within. The Sun is situated two-thirds of the way out towards the edge of the galactic disc, and the Milky Way appears brightest in the direction of the bulge around the galactic centre, which lies in the constellation Sagittarius. Clouds of obscuring dust, such as the Coalsack near the Southern Cross, give the Milky Way a patchy appearance in places.

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The Sun, together with the planets and moons, comets, asteroids, meteoroid streams and interplanetary medium held captive by the Sun's gravitational attraction. The solar system is presumed to have formed from a rotating disc of gas and dust created around the Sun as it contracted to form a star, about five billion years ago.
The planets and asteroids all travel around the Sun in the same direction as the Earth, in orbits close to the plane of the Earth's orbit and the Sun's equator.

Solarization program
More about Solar system

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