KnowraCircular orbitLinked fromLinked fromThe 9 pages that link to Circular orbit, each with the reason it gives.All 9Broader topic 2Related 2Compared with 5Kepler's laws of planetary motionCompared with: A circle is only a special zero-eccentricity case of the first law's ellipse.Orbital eccentricityCompared with: It is the limiting case against which nonzero eccentricity measures elongation.Vis-viva equationBroader topic: Setting the semimajor axis equal to the radius yields its familiar speed formula.Hohmann transfer orbitRelated: The transfer begins and ends in circular orbits.Kepler's third lawBroader topic: For a circle, semimajor axis equals radius, making the law's distance especially direct.Planetary orbitCompared with: It is the limiting case of an ellipse with zero eccentricity.True anomalyCompared with: In a circular orbit, true anomaly advances uniformly, unlike in an eccentric orbit.Bi-elliptic transferRelated: The maneuver begins and ends in circular orbits, whose speeds set the endpoint conditions.Kepler's first lawCompared with: A circle is an ellipse with zero eccentricity, but planets generally have nonzero eccentricity.