# Mean Motion

## Description

In orbital mechanics, mean motion (represented by ) is a measure of how fast a satellite progresses around its elliptical orbit. The mean motion is the time-average angular velocity over an orbit. In particular for circular orbits, the angular velocity is constant, and so it equals the mean motion.

In databases of satellite orbital parameters the mean motion is typically measured in number of revolutions per day.

Related formulas## Variables

n | mean motion (rad/sec) (1/s) |

G | Newtonian constant of gravitation |

M | orbiting body (kg) |

m | orbiting body (kg) |

a | semi-major axis (m) |