So, say we get to Mars. We get our million people on Mars and become an official galactic colonial species, what next? When interviewed for Aeon, Musk had this to say about how he envisions the future of space travel: If we can establish a Mars colony, we can almost certainly colonise the whole Solar System, because well have created a strong economic forcing function for the improvement of space travel. Well go to the moons of Jupiter, at least some of the outer ones for sure, and probably Titan on Saturn, and the asteroids. Once we have that forcing function, and an Earth-to-Mars economy, well cover the whole Solar System. Of course, as well as the rockets, we'll need to kick it up a notch in terms of our terraforming technology to make the other worlds in our solar system habitable. If we can get the technology and finances sorted then taking our little Earthling show on the road has a lot of massive benefits. Aside from expanding our knowledge of the solar system in a tangible, boot-on-ground way, it also allows us to offload our booming population onto other worlds and could well be the key to our survival as a species. Plus, with the colonisation of Mars, we officially become a multi-planet species. The transition will take generations, but it would ultimately be worth it, taking us out into the solar system and beyond. Love all things science? Like us on Facebook and follow us on Twitter for loads more science bits up in your brain parts.