This question already has an answer here:
- Orbit of a double planet 1 answer
If, say, there was a double planet system (not a planet + satellite, but two planets circling each other with the barycenter outside either of the planets, of a relatively high mass ratio), what would determine the speed of their rotations and revolutions?
How close or far could they conceivably be, and would this affect their speed?
Would they be tidally locked?
And, of course, could they support life? (Either one supporting life and the other be barren, or the event that caused the system to form i.e. a meteor induced planetary split resulting in two smaller planets with already established life?)