moons

[badboy4life]

okay once and for all how many moons does the earth have? can someone who is qualified in this area please tell me.

[mibn2cweus]

One . . . and a half

[rojash]

Don't get it mib, that article says "Because it does not orbit the Earth, it is not considered a moon in the normal astronomical meaning of the word."

[jake-the-peg]

It doesn't orbit the Earth but rather one of the Earth/Sun's Lagrange points L4.

So it is a moon in the very loose sense that it orbits a point determined by the gravity of another body.

Consider Pluto/Charon. These two orbit around a point which is between them so they are really twin planets or asteroids (depending on your definition)

The orbit of Cruithne is not independant of Earth but it's not a true Satelite either.

There's a good page on it here - It's in French so this link is via bablefish
http://babelfish.altavista.com/babelfish/trurl _pagecontent?lp=fr_en&url=http%3A%2F%2Fmembres .lycos.fr%2Ffransyl%2Flagrange%2Fcruithne.htm

We keep finding objects in the solar system that don't quite fit into our old notional system of Star/Planet/moon/asteroid/comet and we don't have proper words for them so we end up banging them into a the nearest term that fits.

For what it's worth I'd not call it a moon but probably a Trojan-type object. after the similar asteroids called Trojans that orbit points about Jupiter

[mibn2cweus]

rojash, by "and a half" I was implying that Cruithne was not another moon is the complete sense, only the next best thing in terms of comparison. I leave it up to the reader to decide if it qualifies as a moon until a more concise definition is offered that eliminates or includes it within the context of the definition. Until then I defer to jake-the-peg's explanation.

Please consider it as an offering of what I thought was pertinent information rather than an answer (proper) to the question.