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,
Saturn not as high as those on Neptune. The planet's most famous feature is its prominent ring system that is composed mostly of ice particles, with a smaller amount of rocky debris and dust. At least 62 moons are known to orbit Saturn, of which 53 are officially named. This does not include the hundreds of moonlets in the rings. Titan, Saturn's largest moon, and the second-largest in the Solar System, is larger than the planet Mercury, although less massive, and is the only moon in the Solar System to have a substantial atmosphere. Saturn is a gas giant because it