I know this sounds like an elementary question with an easy answer. However, I was thinking about chaos theory. Planets and stars are always changing so that their gravitational pulls towards other objects varies. Shouldn't the tiniest change between the pull of a star and a planet, or a planet and its moon (change due to rotation or distance [elliptical paths]) cause smaller objects to either get increasingly close or increasingly far from the large objects, per unit time? Thank you in advance!