[bbor]

I think it was a joke, not a argument from authority as a greek :)

That said, I think ChatGPT is right here:

  ...the term "Europans" seems the most appropriate choice for the inhabitants of the Jovian moon Europa. It aligns with the linguistic patterns used for other celestial bodies, maintains clarity by avoiding confusion with "Europeans," and respects the Greek origin of the name "Europa" without introducing non-standard formations.

  Mercury: Mercurians
  Venus: Venusians
  Earth: Earthlings
  Mars: Martians
  Jupiter: Jovians
  Saturn: Saturnians
  Uranus: Uranians
  Neptune: Neptunians
  Pluto: Plutonians
  Moon: Lunarians
  Io: Ionians
  Europa: Europans
  Ganymede: Ganymedians
  Callisto: Callistans
  Titan: Titanians
  Rhea: Rheans
  Iapetus: Iapetians
  Triton: Tritonians
  Eris: Erisians
  Ceres: Cerians