At the end of the Divine Comedy (spoilers lol) it is revealed that the Empyrean and God are ultimately the primum mobile that imparts motion to the rest of the cosmos. When Dante looks back, he sees that it is actually Earth that is flung out to the outer edges of the universe and God is at the center of the universe - this is similar to a geometric transformation called a circle inversion, which is interesting because inversive geometry wasn't discovered until the early 19th century. Satan was therefore cast as far as possible away from heaven, literally the outer edges of the universe and ultimately his junk is the the point at infinity.