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,
Mercury (planet) into an elliptical orbit, then chemical rockets will fire to deposit the mapper probe into a circular orbit. Both probes will operate for one terrestrial year. The mapper probe carries an array of spectrometers similar to those on "MESSENGER", and will study the planet at many different wavelengths including infrared, ultraviolet, X-ray and gamma ray. Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the