The prime purpose of Gravitorium is to let you play with'What If' ideas about gravity and gravitational systems. It's not intended as a serious solar system simulator, though its accuracy is pretty good over modest periods of time (a hundred years or so). But it is quite good enough to get a good general impression of the likely course of events in a particular planetary system. And, best of all, it lets you 'play god' and easily create your own systems.