Most people have made this mistake of thinking Middle-earth is a particular kind of earth or is another planet of the science fiction sort but it's just an old fashioned word for this world we live in, as imagined surrounded by the Ocean.
J. R. R. TolkienAnd here he was, a little halfling from the Shire, a simple hobbit of the quiet countryside, expected to find a way where the great ones could not go, or dared not go. It was an evil fate.
J. R. R. TolkienAnd she looked at him and saw the grave tenderness in his eyes, and yet knew, for she was bred among men of war, that here was one whom no Rider of the Mark could outmatch in battle.
J. R. R. Tolkien