User:Mark Widmer/sandbox

Possible text to add to Hill_sphere page: NEED TO DOUBLE-CHECK this, as it seems counter-intuitive and may be wrong.

The Hill radius is not simply the distance at which the gravitational forces exerted on the satellite by the star and by the planet are equal, but is in fact larger than this distance by an additional factor of $\left({\frac {M}{9m}}\right)^{1/6}$. (The assumption here is that the planet's mass is significantly smaller than that of the star.) This works out to roughly a factor of 6 in the case of Earth and the Sun.