“A non-human species? Hmmmm, must be AI and how convenient is that? Considering AI “on earth” has just recently and hurriedly become a major game changer.
What if the ‘aliens’ are actually robots. They could withstand a stellar long distance ride no problem.................
Humans interpret things they do not understand in terms of current beliefs/technology.
Jacque Vallee wrote a wonderful book “Passport to Magonia” on this topic.
In the Middle Ages the “aliens” were “fairies” and “demons”.
In the 1950s they were “visitors from Venus”.
In the 1960s to the 1990s they were from “other star systems”.
etc etc etc....