What governs the temperature of a planet?
There may be some contributions of heat from heavy collisions with large bodies at different times in the planet’s life. For instance, if something the size of a small moon strikes a planet, It will add a lot of energy to the planet. A massive strike could turn the whole surface of a planet molten by the time the absorbed energy “evens out” across the whole of the surface. Certainly the amount of time that has elapsed since the event will have an effect on surface temperatures because the planet will cool. But you knew that.
