Earth
The Earth is a planet far away from the Mushroom World and is the setting of Mario is Missing and Mario's Time Machine. In both of these games, Bowser steals important artifacts from Earth, causing chaos on the planet. As such, Mario or Luigi must retrieve these items to restore balance to the Earth.
The planet is orbited by one moon (which, interestingly, Mario has also visited).
Appearances outside of games
In the Super Mario Bros. Super Show, Mario and Luigi often try to find their way back to Brooklyn, usually via a warp pipe. In the end of these episodes, the Mario brothers decide to stay so they can protect Princess Peach and the Mushroom Kingdom. Additionally, the live action sequences take place in Brooklyn. Additionally, in the Super Mario Bros. 3 cartoon show, many episodes featured characters using warp pipes to warp back and forth between the "Real World" (Earth) and the Mushroom World.
