OT: Lagrange

I think not. I'm pretty sure that the Lagrange points are only 100% valid for zero-mass satellites.

I dimly remember some comment that if you had six Earths all in the same orbit around the sun, at each other's Lagrange points, that the ensemble would be unstable.

I could be wrong, and I'm too lazy to Google for it.

(Search on Larry Niven's "Known Universe" series, and the arrangement of the home planets of the Pierson's Puppeteers).

Another shot of Drambuie will provide the answer >:-} ...Jim Thompson

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I suspected it was like that.

I started thinking about it because I heard China is planning to "occupy" L4 and L5 to keep anyone else from doing it.

ritto:

Lagrangian points are defined only in a system with two (or more) bodies. You can't have lagragian points with only one body.

You can put something that has a small mass (respect of the other two bodie s) and it stay there. Satellites on L1, L2 and L3 have the same orbital period of the smaller of the big bodies (for sun-earth they will have a orbital period of 1 year, so they don't follow third Kepler law), but they are not stable, you have to use energy to keep a satellite there.

L4 and L5 are stable, meaning that something put around L4 and L5 will orbi t around the lagrangian point. For example there are asteroids in L4 and L5 of the system Sun-Jupiter (aka

r).

Bye Jack

not zero of course, but very small compared to the other 2 objects that cre ates the lagrangian points, so that it doesn't interfere with the other bod ies orbit.

Bye Jack

Since these are unstable, it makes no sense that the Pupptreer's would have built one.... then again he (Niven) already had an unstable ring world, so what the heck.

George H.

Presumably if you have the resources to move planets around your solar system, you have the resources to nudge them back into place when they stray.

Does the article say what the eigenvalues are for an earth-orbit rosette? I could see it taking years before a minor problem became major.