This question already has an answer here:
I'm attempting to write a simulation of a solar system of planets in 2D space that are attracted to each other through Newton's law of universal gravitation.
I know that it is possible to simulate this in Box2D by applying forces between each body in the system each frame, however I've read that Box2D is tuned for objects between 0.1m and 10m - In my simulation I want to be able to simulate the motion of large and small bodies (e.g. planets and artificial satelites).
When such large scales are involved is using Box2D (or an alternative 2D physics engine) to simulate the gravity between bodies in this way a good idea (I know I can scale the system, e.g. so that the sun has a diameter of 10m), or am I better off doing this myself?