FEEL FREE TO USE THIS CODE!!! I've seen some people manually selecting positions to glide to as a way of achieving an orbit. This is a much simpler way to make that code. The sprites are able to move fully off-screen by first switching to a transparent costume larger than the borders, a technique I learned from Griffpatch (thank you @griffpatch), and it's important to make the custom blocks run without screen refresh so the user doesn't see the costume changes. I later plan to implement a tick system that the blocks will trigger on so the orbit of the moon is consistent (currently it is slightly elliptical, but I guess that's accurate to real life lore lol).
Credit to @griffpatch for teaching me how to make sprites move fully off-screen. Make sure to check out his tutorials on YouTube, and sign up for Griffpatch Academy!