starman | Another package manager for HPC warriors

First time asking here. My experience is only "advanced beginner". The question is about the variable storage in the memory due to an object instantiation in Unity.
Need a bit to explain the setup:

In my scene, I instantiate an entire starsystem. The script can create up to 8 planets, each with up to 3 moons and 4 anchors (empty gameObjects). I do not change scenes, I only destroy the starsystem and instantiate the new one, so I need to ensure all old references are gone from memory. I want to be sure that I do not create a memory leak here by stuffing the memory with gameObjects that never get removed.

Below is the part of my script that instantiates the moons, can be called many times within a single system instantiation. The moon gameObject will be "returned" to the caller after instantiation and added to another variable created in the caller, which is it's official variable called planetXMoonY, and can only exist once per system and will be nulled before a new system instantiation.

In Version 1, I create the temporary variables within the method, and in version 2, I created them outside and first reset them before instantiating stuff.

How is this handled in memory ? Am I seeing it correct that in version 1 after a while there could be technically dozens or more newMoon GameObjects in memory ? Same name, but of course with separate instance ID, and I will filling up the memory.

What happens when the object planetXMoonY is destroyed ? When I understand it correctly, there is no more connection to the newMoon variable , but the planetXMoonY reference will be removed in time by the GC(). But will the newMoon variable ever be deleted from memory without a direct call setting it to null ?

So I thought maybe Version 2 is an improvement. Does it help to reset it to null first to ensure the garbageCollector removes all newMoons in time, since they aren't needed after returning the gameObject, there are just here for instantiation purpose. But am I still creating dozens in this way, or just one ?

I hope the question is clear enough. I seem to miss a bit of basic understanding in memory usage here. I think I'm missing a really important knowledge piece here on how to correctly and safely create variables, and I want to ensure my future workflow is improved. Thank you in advance for helping.

B/R Starman

Version 1: