In astrodynamics, an orbiting body is any physical body that orbits a more massive one, called the primary body. The orbiting body is properly referred to as the secondary body (<math>m_2</math>),<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> which is less massive than the primary body (<math>m_1</math>).
Thus, <math>m_2 < m_1</math> or <math>m_1 > m_2</math>.
Under standard assumptions in astrodynamics, the barycenter of the two bodies is a focus of both orbits.
An orbiting body may be a spacecraft (i.e. an artificial satellite) or a natural satellite, such as a planet, dwarf planet, moon, moonlet, asteroid, or comet.
A system of two orbiting bodies is modeled by the Two-Body Problem and a system of three orbiting bodies is modeled by the Three-Body Problem. These problems can be generalized to an N-body problem. While there are a few analytical solutions to the n-body problem, it can be reduced to a 2-body system if the secondary body stays out of other bodies' Sphere of Influence and remains in the primary body's sphere of influence.<ref>Template:Cite book</ref>
See alsoEdit
- Barycenter
- Double planet
- Primary (astronomy)
- Satellite
- Two-body problem
- Three-body problem
- N-body problem