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 mistake that men make is that they do not believe in theater. Otherwise, they would know that every man is allowed to play the celestial tragedies and to become god. All he has to do is harden his heart.”
—Albert Camus (1913–1960)
“I count him a great man who inhabits a higher sphere of thought, into which other men rise with labor and difficulty; he has but to open his eyes to see things in a true light, and in large relations; whilst they must make painful corrections, and keep a vigilant eye on many sources of error.”
—Ralph Waldo Emerson (1803–1882)