At the risk of taking a geocentric position, my gut feel is Terra -> Luna -> Sol -> Astra. Sorting algorithm is distance from observer.
Size wise Astra is not categorically bigger than Sol, both in absolute terms and the observed size.
Yeah, this was my initial thought as well... I guess they didn't ask anyone before choosing the new naming scheme. But that isn't particularly surprising.
Size is by far the most obvious one, at least for me.
It doesn't help that the moon and sun have roughly the same apparent size in the sky
Why on earth (no pun intended) would anyone do this?
[dead]
Astra is latin for "stars", so basically the Galaxy (or Universe as a whole) which is categorically bigger than Sol, the sun, a single star.
The naming makes perfect sense to me, the sorting algorithm is size, both for the names and for the models themselves. Smaller things represent smaller models, and vice versa.