User blog comment:High King Ithilion/The Ithilion Eleruth Collection/@comment-30079501-20170323185632/@comment-26149161-20170325123955

But they don't need lore mechanics to exist. They function the same, and do all the same things. The way that the sun and moon stand in space doesn't matter in this instance, because they are jsut the Sun and Moon, with all their properties.

And the "later the writing, the more canon" is actually agreed on among the vast majority of Tolkien scholars. That would make Arda a Solar System.

Ithilion, Discussions Moderator (Auta i lome) 12:39, March 25, 2017 (UTC)