The meaning of 星人 vs 宇宙人


I've come across 星人 and 宇宙人 for describing aliens. What's the difference in
the meaning of these words?




星人 is never used alone. It is used with specific names of planets like
火星人{かせいじん}(Martian), 金星人{きんせいじん}(Venusian), or
[ナメック星人](https://dic.pixiv.net/a/%E3%83%8A%E3%83%A1%E3%83%83%E3%82%AF%E6%98%9F%E4%BA%BA).
It means the habitants of a particular planet. FYI earthlings are 地球人.

On the other hand, 宇宙人 usually refers to (extraterrestrial) _aliens_ and is
used by itself.




星人 is never used alone. It is used with specific names of planets like
火星人{かせいじん}(Martian), 金星人{きんせいじん}(Venusian), or
[ナメック星人](https://dic.pixiv.net/a/%E3%83%8A%E3%83%A1%E3%83%83%E3%82%AF%E6%98%9F%E4%BA%BA).
It means the habitants of a particular planet. FYI earthlings are 地球人.

On the other hand, 宇宙人 usually refers to (extraterrestrial) _aliens_ and is
used by itself.

