The orb represents the earth it is true, but digging a little deeper, does the orb (earth) represent the divine rule of the king and his status as a representative of the god (s), or does it represent the agenda of the one world government; a new world order?
would the coronation of a king be a sort of mock coronation of a god, a symbolic type of what is in store for the new monarch?
The cross on the orb could also represent the sun, but that is a whole different post.