I wrote:
> His calculation was off by roughly factor of two, but our knowledge of the > sun's distance has improved immeasurably since then, and we also know the > mass of the earth more accurately. > I should say we know the gravitational constant G more accurately. In the first approximation you ignore the mass of the planet. Strictly speaking the sun and planets orbit around their common centers of gravity, which must be very complicated indeed. - Jed
