Thanks for the clarification! Is ‘aliens’ the same word in Portuguese or did the artist use an English word or was this a translation?
I think it’s a loan word. The root “alien” exists in words like *alienado* (alienated) or *alienação* (alienation), but as a single word alien/aliens I think comes from English.
A bit of a correction, alien has its roots in Latin, alius (other) -> alienus (belonging to other), which spread over the places the Romans conquered. Since it’s Latin, it’s also the why most legal documents love using “alienate” when it comes to transferring ownership of stuff
No idea when alien started to be used to refer to extraterrestrials.