Darren New <dne### [at] sanrrcom> wrote:
> Warp wrote:
> >   Interesting tidbit: Did you know that Moon's orbit around the Sun is
> > completely convex? (In other words, the curvature of the orbit never
> > changes sign.)

> Yes, that's what I'd read about. In essence, it's orbiting the sun as it 
> wobbles back and forth across the earth's orbit, rather than actually 
> orbiting the earth. That's why I thought we might be much closer to losing it.

  "Rather than actually orbiting the Earth" is incorrect. It *is* orbiting
the Earth. The Earth-Moon system is orbiting the Sun. Ergo the Moon is
*also* orbiting the Sun. In other words, the Moon is orbiting both.

  The orbital period of the Moon around the Earth is so slow that if we
trace the Moon's orbit around the Sun, it actually results in a completely
convex shape. However, that's more a curiosity than anything else. It
doesn't mean it's not "actually orbiting the Earth".

-- 
                                                          - Warp

Post a reply to this message