Earth is the only planet not named after a pagan god.
All other planets are named after gods from Greek and Roman mythology. The name Earth comes from the Anglo-Saxon word Erda (Erdaz), which means ground or soil. The word changed to Eorthe or Erthe in Old English and to Erde in German. In Roman mythology, the goddess of the Earth was Tellus, the fertile soil, and in Greek Gaia, Mother Earth.
