Mars is the fourth planet from the Sun and one of two bodies (along with the Moon) to undergo extensive terraforming.
Beginning in the early 2000s, Mars was colonized by various Earth powers before finding itself independent following the end of the Great War in 2054. After several decades of independence, it was again colonized for its resources in the First Martian War after the re-emergence of major spacefaring powers such as the New Frenco Empire and Luna.
Mars is habitable to human life, with an atmospheric pressure which is breathable in the lowlands but which requires an oxygen supply in the highlands. Much of the planet is cold and dry, though some areas may experience mild rainfall. An axial tilt similar to that of Earth results in seasons. Powerful dust-storms are a common occurence.