In this reference it says that Bart saw Earth but it might of been a similar planet. No known planet (in 1994 when it aired) to have continents. Their is a satelight orbiting it (pardon the spelling of Satelight) so it must be known by people on Earth. So this means it HAS to be Earth and not a similar planet.
Here is the exact picture. You see what i am talking about. (A bully user (talk) 01:52, December 3, 2012 (UTC))