The Expanse (novel series) a future in which humanity has colonized much of the Solar System, but does not have interstellar travel. In the asteroid belt and beyond, tensions are rising between Earth's United Nations, Mars, and the outer planets. The series initially takes place in the solar system, using many real world locations such as Ceres and Eros in the asteroid belt, several moons of Jupiter, with Ganymede and Europa the most developed, and small science bases as far out as Phoebe around Saturn and Titania around Uranus, as well as well-established domed settlements on Mars and the Moon. As the series progresses,
Orbit of the Moon moves in its orbit around the common centre of gravity. The Sun's gravitational effect on the Moon is more than twice that of Earth's on the Moon; consequently, the Moon's trajectory is always convex (as seen when looking Sunward at the entire Sun–Earth–Moon system from a great distance outside Earth–Moon solar orbit), and is nowhere concave (from the same perspective) or looped. That is, the region enclosed by the Moon's orbit of the Sun is a convex set. Orbit of the Moon The Moon orbits Earth in the prograde direction and completes one revolution relative to the stars in about