Hill sphere
Region in which an astronomical body dominates the attraction of satellites
Summary
The Hill sphere is a common model for the calculation of a gravitational sphere of influence. It is the most commonly used model to calculate the spatial extent of gravitational influence of an astronomical body (m) in which it dominates over the gravitational influence of other bodies, particularly a primary (M). It is sometimes confused with other models of gravitational influence, such as the Laplace sphere or the Roche sphere, the latter of which causes confusion with the Roche limit. It was defined by the American astronomer George William Hill, based on the work of the French astronomer Édouard Roche.
Originally created by Nealmcb
6/13/2004, 5:14:37 AM
Modified
5/12/2026, 12:19:35 AM
Recent revisions
/* Regions of stability */ remove weird tag
/* Example and derivation */ copy content from [[comet]]
Added Haumea, Makemake, Sedna and Planet Nine (hypothetical) to the list.
MOS:OL
/* Hill spheres for the solar system */ uppercase per proper name and Wikipedia style (Solar System)
Fixed Mars' value
Added a column in the table for the ratio of the farthest moon to the hill sphere radius
/* Definition */ clarified true anomaly
/* Definition */ clarified "anomaly" means "true anomaly" ("anomaly" is too vague and should be avoided whenever possible)
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/* Definition */ exact formulation
/* Definition */ Example calculation for the Earth Moon system
/* Regions of stability */ Changed some sentence structure and some grammar
Added article-number. Removed parameters. | [[:en:WP:UCB|Use this bot]]. [[:en:WP:DBUG|Report bugs]]. | Suggested by Whoop whoop pull up | [[Category:Orbits]] | #UCB_Category 27/125
Corrected two occurrences of "m2" to "m_2".
Duplicate word removed
