Other Contenders
The Flag of the United Nations has been used to indicate world unity, although it technically only represents the United Nations itself. It has a geographical representation of the planet, and its high visibility usage makes it a well-known contender for representing Earth. Indeed, during the planning for NASA's moon landings of the 1960s, it was suggested that a UN flag be used in place of the flag of the US.
Read more about this topic: Flag Of The Earth