User:Mark Widmer/sandbox: Difference between revisions

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(Added potential new sections for Hill_sphere article)
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==Hill sphere of objects that orbit Earth==
==Hill sphere of objects that orbit Earth==


The Moon
The Moon -- added to article


Artificial satellites in low-Earth orbit
Artificial satellites in low-Earth orbit


Satellites in low-Earth orbit are too close to Earth to ever have smaller objects orbiting it. For a satellite of mass 1000 kg orbiting Earth at an altitude of, say, 400 km, the Hill radius is calculated to be only 26 cm, much smaller than the typical size of such a satellite. Moreover, as both the Hill radius and the size of the object (of fixed density) increase in proportion to the cube root of the mass, an object at this altitude will always be larger than its Hill radius no matter what its mass, and therefore be unable to have satellites of its own.


==Hill sphere of an object orbiting with another comparable-mass object==
==Hill sphere of an object orbiting with another comparable-mass object==

Revision as of 19:52, 14 August 2021

Sandbox. Mark Widmer (talk) 01:17, 5 August 2021 (UTC)

Draft for additions to Hill_sphere New sections:

Hill sphere of the Sun

The Sun has a Hill sphere as well, though the formulas listed earlier are not applicable since the Sun does not orbit a compact object. Two considerations that determine the Sun's Hill sphere are (1) that the Sun orbits the center of mass of the extended distribution of objects that makes up the galaxy, and (2) the nearest star, Alpha xxx, can affect the orbits of objects far enough from the Sun, even though the Sun does not orbit Alpha xxx.

? Calculation/estimate of Sun's Hill radius due to Alpha Centauri?

Hill sphere of objects that orbit Earth

The Moon -- added to article

Artificial satellites in low-Earth orbit

Satellites in low-Earth orbit are too close to Earth to ever have smaller objects orbiting it. For a satellite of mass 1000 kg orbiting Earth at an altitude of, say, 400 km, the Hill radius is calculated to be only 26 cm, much smaller than the typical size of such a satellite. Moreover, as both the Hill radius and the size of the object (of fixed density) increase in proportion to the cube root of the mass, an object at this altitude will always be larger than its Hill radius no matter what its mass, and therefore be unable to have satellites of its own.

Hill sphere of an object orbiting with another comparable-mass object