I do not understand how an Astrologian does its Magic.

[Zohar_Lahar]

This is what Astrologians believe; the quests do make that clear. I just have my doubts that it's true. If one can truly draw aether directly from ... let's be conservative and just say "farther away than the moon" ... why not places you've been before? Why not cast all fire magicks drawing from Thanalan, for example? I can't shake this feeling that if you can draw aether from space, Black Mages are nothing; something about it sits wrong with me.

Much of my doubt stems from the fact that other things Astrologians believe don't seem quite fully true, either. For example, we know that the seeds of faith that eventually became The Twelve have changed much over time. The Astrologians see the Third Heaven as a realm contains a giant clockwork tower built by Byregot and assailed by Rhalgr's levinbolts, but their understanding of the constellation and artworks associated with it are clearly just cultural memories of Dalamud transferring energy to the Crystal Tower. I choose to keep faith in many things in this game, even when given reason to doubt them - but man is fallible and traditions are often at least a LITTLE askew of the whole truth.

[----]

One kooky sentiment that I really liked was that perhaps they are attuning to the energies represented in those stars by bathing in their starlight, which might contain tiny, tiny traces of aether for all we know. After that, they can recall it and attune to it - like being tainted by a primal's death mist. But I literally made that up, so...

I think it is specifically drawing aether from the starlight that has traveled to Hydaelyn's surface. That is, after all, the tangible phenomenon an Astrologian is observing when you attune to the heavens. And if the Crystal Tower can draw aether from sunlight, it should be possible to extract aether from starlight.