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:
“Man will rise, if God by exception lends him a hand; he will rise by abandoning and renouncing his own means, and letting himself be raised and uplifted by purely celestial means.”
—Michel de Montaigne (1533–1592)
“Thought dissolves the material universe by carrying the mind up into a sphere where all is plastic.”
—Ralph Waldo Emerson (1803–1882)