Of course he’s from Earth! What sort of question is that? He looks at the man with increased suspicion, though it shifts quickly to indignation as he continues. As if it were not bad enough that the townspeople hate him for being foreign, now this stranger is calling things alien with some sort of strange look on his face.

“I’ll have you know that I am an alien,” he snaps. “A foreigner. An immigrant. Whatever you prefer.” It does not occur to him that Bucky means ‘from outer space’ — how could it, when he predates that meaning of the word by fifty years?