
It's a geocentrist model of the universe, and to me it seems certainly more reasonable than the claims of modern "science". I question the existence of other galaxies, as NASA has a proven track record of lying and hoaxes (ex. Moon Landing), and they offer no convincing evidence (CGI renders don't count).
Notably, it features prominently in the Dante's
Paradiso, and as an aside, it was through reading that book that I first learned about this system.
I'm interested to hear the opinions of others here on the forum on this subject, since I am interested in the subject but (to my knowledge) didn't see it come up during the recent Flat Earth debates.