Gm!
The core of the earth will be in very much the same state is in now by the time the sun enguls this planet, by our current best models. We have lots of time to refine them though, as this is approximately 5 billion years out.
Since we only have a sample size of one, let's assume nature can go from nearly lifeless to creating and supporting sentient, intelligent life, that is able to contemplate astronomy, once every 65 million years. (Admittedly quite generous) if humans gk extince tomorrow, this would give life 75 more tries at getting off this rock before it become uninhabitable. Thats how long 5 billion years is
Mars does not have tectonic motion, as its plates have settled millions of years ago. Earth will never have time to reach that state.
The united states just crossed 38 Trillion dollars in national debt. 38 trillion is 7600 x the size of 5 billion