Editing Orbiting body

{{Refimprove|date=December 2009}}

In [[astrodynamics]], an '''orbiting body''' is any [[physical body]] that [[orbit]]s a more massive one, called the [[primary (astronomy)|primary body]]. The orbiting body is properly referred to as the '''secondary body''' (<math>m_2</math>),<ref>{{cite web |title=Dictionary of Technical Terms for Aerospace Use |url=http://er.jsc.nasa.gov/SEH/s.html |publisher=[[NASA]] |access-date=2010-05-11}}</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 (geometry)|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]], [[natural satellite|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>{{cite book|author=Curtis, Howard D.|title=Orbital Mechanics for Engineering Students, 2e|publisher=Elsevier|location=New York|date=2009|isbn=978-0-12-374778-5}}</ref>    

==See also==
*[[Barycenter]]
*[[Double planet]]
*[[Primary (astronomy)]]
*[[Satellite]]
*[[Two-body problem]]
*[[Three-body problem]]
*[[N-body problem]]

==References==
{{Reflist}}

{{DEFAULTSORT:Orbiting Body}}
[[Category:Orbits]]
[[Category:Astrodynamics]]
[[Category:Physical objects]]


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