So far as I can tell we will have Venus, Earth, The Moon, and Mars to explore. That is potential 329 million square miles of area. I'm sure that the entire surface on each will not be accessible. Still, there is a lot of area for them to play with. I saw an article earlier that each planet will be about the size of the Halo Reach game. Does anyone have any idea what that translates to in sq mi/km?