Kepler's laws

From Citizendium, the Citizens' Compendium
Jump to: navigation, search
This article is a stub and thus not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
This editable Main Article is under development and not meant to be cited; by editing it you can help to improve it towards a future approved, citable version. These unapproved articles are subject to a disclaimer.

Kepler's laws of planetary motion, or simply Kepler's laws, are three laws stated by the German astronomer Johannes Kepler. These laws govern the motion of the planets around the sun. Stated briefly, the laws are:

  1. The orbit of a planet is elliptical, with the sun at one of the two foci of the ellipse.
  2. The line joining a planet and the sun sweeps out equal areas in equal intervals of time.
  3. The square of the periodic time of a planet is directly proportional to the cube of the semi-major axis of its elliptical orbit.