system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we have specific names for other planets' moons but we simply call ours "the moon"?
gpt
When ours was named, people thought it was the only moon in the whole universe, because telescopes had not been invented.

Once people realized other planets had moons, they had to name them -- but ours was already "the moon" and attempts to give it other names in English (such as Luna) were ignored by most people.