The Orion Arm, also known as the Orion Region, is the name given to the extent of interstellar space currently inhabited by humanity. While the region covers an extremely vast distance, it represents only a small section of the Milky Way galaxy. Within the Orion Arm there lie several thousand star systems, with millions of planets, moons, and all manner of asteroid belts, comets, and other celestial phenomena. Only a tiny fraction of these star systems contain habitable planets, with roughly three hundred systems currently inhabited by humans. Estimates see that number rising to over four hundred within the next fifty years.