What I don’t understand is how you define a single point (even if the point spans a million years) of “when the solar system formed.” They say the chemical composition of the Earth solidified “only 3 million years after the solar system formed” — isn’t the formation of the planets itself part of the formation of the solar system? How does one define the moment of formation? Or does this mean that we know with certainty that there was no physically consistent body one could identify as “Earth” 3 million years prior, and then within those 3 million years, it coalesced and solidified?