The Mean Anomaly of an object describes the object's position along its orbit. It represents the fraction of the object's Orbital Period that has elapsed since the object passed its pericenter (the point where the object was at its closest distance to its Orbital Parent). For example, when one quarter of an object's orbital period has elapsed since it was at pericenter, the Mean Anomaly is equal to 90°.

Mean Anomaly is one of six orbital elements that describe an object's orbit.

Property Details


The Mean Anomaly property is located in the Orbital Elements section of the Motion tab of an object's properties panel, if that object has an Orbital Parent.


Mean Anomaly is an angle, and can be viewed or edited using the following units:

  • Radians (rad)
  • Degrees (°) = (180/π) rad

For a circular or elliptical orbit (where Eccentricity < 1), the Mean Anomaly is defined in the range from -180° to +180°, or -π to π rad. For a parabolic or hyperbolic trajectory (Eccentricity >= 1), the Orbital Period is not defined, and the Mean Anomaly may have any value from -∞ to ∞.

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