There was also that amazingly complicated system of Ptolemy, with epicycles (which assumed a motionless earth). I think the reason that notion the earth might be orbiting the sun wasn't taken seriously was suggested in that website about Aristotle in one of my earlier posts. If we were in orbit (the thinking went), our position would shift greatly every six months, so we should (they thought) be able to see the apparent positions of the "fixed" stars shifting as our viewpoint changed. As we now know, the closest stars do indeed undergo a parallax shift, but it's tiny, and it requires a good telescope and photographic records to reveal this.
Do you find any of the other astronomical observations in Enoch curious, given its antiquity?