This image shows green and red circles rotating in opposite directions CCW and CW. On the other hand, the green ones are always in contact with the red ones. So, if just one circle begins to rotate the rest will follow suite. There are infinite varieties that these circles can be arranged and formed at various different sizes. However, the red can never come in contact with another red and the greens likewise.
There seem to be some relative centers but I can't find any absolute center(s).