Skip to main content
Select Source:

quadrature

quadrature, in astronomy, arrangement of two celestial bodies at right angles to each other as viewed from a reference point. If the reference point is the earth and the sun is one of the bodies, a planet is in quadrature when its elongation is 90°. As viewed from the earth, the half-moon is in quadrature to the sun. The inferior planets (Mercury and Venus) never reach quadrature; the superior planets each have two points of quadrature in their orbits.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"quadrature." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 17 Aug. 2017 <http://www.encyclopedia.com>.

"quadrature." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (August 17, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/quadrature

"quadrature." The Columbia Encyclopedia, 6th ed.. . Retrieved August 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/quadrature

quadrature

quadrature See IMAGINARY COMPONENT.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"quadrature." A Dictionary of Earth Sciences. . Encyclopedia.com. 17 Aug. 2017 <http://www.encyclopedia.com>.

"quadrature." A Dictionary of Earth Sciences. . Encyclopedia.com. (August 17, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/quadrature

"quadrature." A Dictionary of Earth Sciences. . Retrieved August 17, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/quadrature