Each frame, I calculate the velocity (x/y) of each objects based on their distance between the object and the center (target). Then, I apply a linear velocity on the body + the rotation based on the angle. I've used Box2D for that

Here is a part of the code (lua, LÖVE framework) : https://gist.github.com/psych0pat/2b7c8f52b9191f28ef8f

It's a bit dirty but it's working :)