Alien Theorists Theorizing

Earth is a lucky place. Set in the medium range from a star so that carbon based life can flourish, a large enough satellite, the Moon, to deflect incoming meteors and a stable magnetic field to ward off the worst of cosmic radiation. Despite all that, there have been several massive extinction events, that we know of, which have nearly wiped out all life on our little blue space marble. What if the next texas sized chunk of rock sailing through our solar system has our name it? Looking to science-fiction, we find that the threat of total human extinction has been mitigated due to the fact that our society has taken the leap to settle out among the other planets and moons in our cosmic neighborhood. Cities on a red Mars turned green, hollowed out asteroids where we mine for ice, and jovian moons turned to farming worlds. How far are we from turning science-fiction scenarios into reality? What challenges face our civilization as we take our first steps towards becoming an interplanetary empire? What technology