system
Given the following post, respond as if you're commenting on Reddit:
human
Has Earth always been in the Sun’s habitable zone? If not, when did it start to occupy the Goldilocks zone?
gpt
Earth’s orbit has not changed since its creation, though that is basically by definition as something is not a planet until it has cleared out everything from its orbit. That said, you may be interested in the faint young sun paradox. The sun was  dim early in earth’s history, and so liquid water shouldn’t have been possible as early as we find evidence for it. So in a way the earth wasn’t always in the Goldilocks, but not due to orbits but solar output.