meanAnomaly

Given a predicate that represents a relationship or action between entities, generate a one-sentence description explaining its meaning.  
# Instructions
Focus on describing the relationship, not the entities themselves. 
# Response Format
Begin the description with \' Indicates...\'

Predicate: meanAnomaly

Indicates the angular position of an orbiting body along its elliptical path, measured from periapsis as if it moved at constant angular speed in a reference circular orbit.