I personally think we should aim for a word that doesn't feel like it came from our modern languages. Something with a bit of a bite to it that makes you wonder 'well who the hell named it that'? The name 'Earth' must have come from some source, it spread through europe and became variants like Arth and Urde and eventually came back together once we again shared language.
My suggestion remains: Tarisch (Tah-Reesh)
though nothing says the various cultures couldn't have variant names. Tarith, Vareesk, Tolish, Dorich, etc.