Fate of the Moon

trakar wrote:

I probably should have just responded that, "the mechanism behind the
Moon's recession is fairly well understood, and it does not in itself,
allow for the moon's eventual escape from the Earth's gravity."

One thing he might have been talking about is the tidal evolution
of the Moon moving it so far outward that the lunar orbit might become
unstable due to solar perturbations. A simple esitmate of the
tidally-locked end state of the Earth-Moon system predicts an
Earth-Moon distance of around 93 Earth radii (it's currently about 60
Earth radii out), and a "day" = "month" = 52 current days long. If you
take the Earth's core into account, it's a little closer (a_final =
86.4 Earth radii & "month" = 46.8 current days long), but it's still
way out there. Earth's current Hill sphere limits the stability of
orbits: roughly (i.e., empirically), orbits inside 1/3 a_hill are
stable in a long term sense, while those outside are not. 1/3 a_hill
for the Earth is about 78 Earth radii, so you're right on the edge of
stability (probably beyond it).
To really figure out of the Moon would ever get outside that
stability limit, you have to consider the time evolution of the system
with both lunar & solar tides. It's not a case of one functioning at
one time and a second mechanism taking over later, but a shift in
dominance. And this shift may allow the Earth to retain the Moon.

I had found several supporting sites, unfortunately I also found several
university sites that had misleading and even incorrect information up
on their websites,

I'd be *very* curious about these. Can you provide any URL's?

--
Brian Davis