User blog comment:Gundam Legilis/Questions about Remnant/@comment-25405817-20140925204257

Maybe the map isn't centered on the world's "Greenwich Line" (Note the quote marks, as in "I know there isn't a greenwich line in remnant because it isn't our planet")

Also, In chapter 9 (vol 1), you can see a Globe on Professor Port's desk, so that's as good a reference as any.