Earth's other moon and its crazy orbit

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31 points·ChuckMcM··6 comments

The title is definitely a misnomer as 3753 Cruithne isn't a satellite of earth and isn't affected by earth's gravity (in any impactful way).

For a natural object that is affected by earth's gravity, check out 2010 TK7 [0]. It is the only known object at one of earth's Lagrangian points and is our only Trojan.

[0] http://en.wikipedia.org/wiki/2010_TK7

I would argue that the orbital resonance necessarily is the result of Earth's gravity.

While the orbital mechanics are interesting, calling this asteroid Earth's moon is stretching the definition of a moon quite a lot. The Cruithne orbits the sun, not Earth. As Wikipedia puts it:

The key difference between a satellite and a quasi-satellite is that the orbit of a satellite of Earth fundamentally depends on the gravity of the Earth–Moon system, whereas the orbit of a quasi-satellite would negligibly change if Earth and the Moon were suddenly removed because a quasi-satellite is orbiting the Sun

https://en.wikipedia.org/wiki/Other_moons_of_Earth#Quasi-sat...

If you're going to call something a "moon" of Earth merely because it's in an orbital resonance, then by the same argument, Pluto is a moon of Neptune.

I guess that's the end of the argument on if Pluto is a planet :(

That's no moon.

Still a vary cool orbit you need to see in 3D to really follow though.

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