Puzzle 29: Lunar Phase

I completed al the puzzels but I am stuck on 29. Despite the hint, the reading of the extended hint and even the solution back in the book I still have no clue…

Do you need to shift the letters? Can anyone help me to solve this one and explain what I have to do?

LUNAR = ALNRU once the letters are sorted in alphabetical order.
Try to understand the relation between the letters and the symbols.

In the first line, if the starting letter A = eclipse (no moon), why is L to this symbol?

Thanks Liam, the alphabetical order triggered me. So the letter A is every time the starting point going to B, C, D, etc in clockwise direction following the different moon phases. I was thinking to difficult so thanks again now I have solved this one too!