I was looking to see if I could simulate orbits or gravity at least in Blender. Is it possible to set an object as a gravitational source, and have other objects be affected by it realistically? I know there is a gravity variable that effects things in physics sims obviously but can gravity be emitted by an object?
You could use a force object as the source of gravity, there is a "Gravitation" check box you can use to make the force proportional to distance. Turn off global gravity (in the Scene tab). Giving rigid body objects an initial velocity is tricky but you can use the hack described in this answer:
A quick implementation of this concept:
However, this falls short of an "actual simulation" because both objects should be attracted to one another. Perhaps it is possible to create a gravity force object for each mesh in your sim, and parent the force objects to the meshes?
Are you trying to make GFX? I believe the best way to do that would be to animate it if you're making an animation, I don't really think there is a way to make gravity generate from an object, the only way objects "move" is when you move it or you make an animation and the object moves in it. Such as, depending on what planet the animation is on, animate them jumping to certain heights then falling or something else of the sort. Hope this helped!