Hill spheres of selected solar system objects

[EarthMoon]

A hill sphere is "the region around a planetary body where its own gravity (compared to that of the Sun or other nearby bodies) is the dominant force in attracting satellites, both natural and artificial." (Wikipedia).

The radii have been calculated using a formula which can be found in the German Wikipedia article about hill spheres:

hillsphere-formula.png (1.85 KiB) Viewed 5010 times

The masses of the selected objects and their distance to the parent object have been taken from A fandom page, NASA fact sheets and the English Wikipedia.

This addon adds those hill spheres as green transparent spheres to Celestia to the objects listed below. They are not clickable, but can be accessed by pressing Enter, typing " Hill Sphere - <object>" (note the space before "Hill"!), where <object> is the actual name of the object, e.g. " Hill Sphere - Earth" for the hill sphere of the Earth, pressing Enter again and pressing G (goto).

List of objects:

Code: Select all

Sol/Jupiter
Sol/Saturn
Sol/Neptune
Sol/Uranus
Sol/Earth
Sol/Venus
Sol/Mars
Sol/Mercury
Sol/Jupiter/Ganymede
Sol/Saturn/Titan
Sol/Jupiter/Callisto
Sol/Jupiter/Io
Sol/Earth/Moon
Sol/Jupiter/Europa
Sol/Neptune/Triton
Sol/Pluto
Sol/Uranus/Titania
Sol/Uranus/Oberon
Sol/Saturn/Rhea
Sol/Saturn/Iapetus
Sol/Pluto/Charon
Sol/Uranus/Ariel
Sol/Uranus/Umbriel

The moon is about 1/4 of the distance of the hill sphere

Hill spheres of all planets (except Mars) as seen from Mercury (they appear bigger than I thought)

The hill sphere of Mercury is rather small compared to the one of the Earth and the orbit of the moon
(Made with an nearly-orthographic low-FOV high-distance view, cel://Follow/Sol:Mercury/2023-09-07T22:54:39.03129Z?x=AABgZMyv1T50/f///////w&y=AADeET63lz7X/////////w&z=AACoSNMf+5sq/////////w&ow=0.5859658&ox=-5.2321804e-05&oy=0.8095087&oz=-0.036603574&fov=0.03042723&ts=1&ltd=0&p=0&rf=71161747&nrf=255&lm=6&tsrc=0&ver=3)