Celestial Sphere

In astronomy and navigation, the celestial sphere is an imaginary sphere of arbitrarily large radius, concentric with the observer. All objects in the observer's sky can be thought of as projected upon the inside surface of the celestial sphere, as if it were the underside of a dome or a hemispherical screen. The celestial sphere is a practical tool for spherical astronomy, allowing observers to plot positions of objects in the sky when their distances are unknown or unimportant.

Read more about Celestial Sphere:  Introduction, Celestial Coordinate Systems, History, Star Globe

Famous quotes containing the words celestial and/or sphere:

    The stillness was intense and almost conscious, as if it were a natural Sabbath, and we fancied that the morning was the evening of a celestial day.
    Henry David Thoreau (1817–1862)

    No person can be considered as possessing a good education without religion. A good education is that which prepares us for our future sphere of action and makes us contented with that situation in life in which God, in his infinite mercy, has seen fit to place us, to be perfectly resigned to our lot in life, whatever it may be.
    Ann Plato (1820–?)