[snarks_when_bored]

The center of mass of a gravitating body is the 'point source' of the body's gravitational influence, so the volume of the body turns out to be irrelevant in calculating the body's gravitational influence.

A nice diagram from here:

[jimt]

Nice diagram, by the way !

[steveo]

Ahhh yas... the old inverse square law... I know it well yas...