Hiif we have an object in deep space with no gravitational pull from anything. And this object fires a cannonball into orbit i.e. not fast enough for escape velocity but fast enough to go into an elliptical orbit. lets say the cannonball is 1/1000th the mass of the object. so the cannonball will set off at 1000xm/hour and the object at xm/hour in the opposite direction. does the fact that the largest mass is moving away from the cannonball have any bearing on the orbit?would the aphehelion be further away than if the larger object wasn't moving? and also would the perihelion be closer. Does this make the orbit longer or shorter? does the shortening or lengthening continue? i.e. do the objects eventually collapse into each other or do the drift apart?