It is possible that the traveler does not move, assuming that it has the ability to ( as we know from the grimoire) the state of perpetual rest can cause an object that big to generate a fairly small gravitational pull, now if your referring to why it doesn't get pulled into earths gravity, again the mass Is so high it hardly matters

If the magic ball of light is able to change how gravity works on at least the earth's moon maybe more and bring atmosphere and life to all the planets in the solar system. Then it can probably not destroy a planet just by being near it.

Space magic swag, most likely.