The final panel of this chapter highlights something that is a little sad and inevitable. Today pretty much everyone knows about how the universe looks like to an extent, but nearly nobody possesses the ability to read the stars.
Based off the house of Piast and the level of technology showed in the manga, we can assume it takes place shortly before the telescope revolutionized sailing and astronomy, the late 14th or early 15th century. During that time, people used to know the night sky like the inside of their pocket, they could memorize entire books.
This manga is of course some kind of alternate reality with inaccuracies but it's still very unique and I'm happy we're able to read it and even got an anime out of it, rather than yet another self insert isekai