[TML] Planets in binary systems

[Timothy Little]

On Sun, Mar 02, 2008 at 12:53:10AM -0800, shadow at shadowgard.com wrote:
> Most notable exception is the Earth/Moon system. But then again
> careful analysis shows that the moon doesn't really orbit the earth,
> it just shares an orbit with Earth.

If the Moon's orbit were perturbed, it would remain gravitationally
bound to the Earth.  It is only weakly bound, true, but still bound.


> There *are* no *solvable* general equations for the three body
> problem.

There are solutions for the three body problem in the simple case
where all three rotate about a barycenter with constant angular
velocity.


> The Lagrange point solution is a special case and *requires* those
> substantial mass differences to work.

Only for stability (which only applies to the L4/5 cases anyway).


- Tim