Solar System (fictional)

The Solar System is the system in which the Earth is located. It has 12 planets: 6 terrestrial planets and 6 gas giant planets: as well as the Asteroid Belt between Mars and Hera, and the Kuiper Belt between Neptune and Erebus.

Vulcan
Vulcan is the closest planet to the Sun, and the smallest planet in the Solar System. Due to being too close to the Sun to reliably see without a telescope, Vulcan was not discovered until 1860 by French scientists. Due to being extremely close to the Sun, Vulcan is extremely hot, and has a magma ocean. It has no moons.

Venus
Venus is the third planet from the Sun. It is similar in size to Earth, but is extremely hot and has an atmosphere of toxic gas; NASA attempted to land a rover here, like they have multiple times on Minerva and Mars, but it was melted in seconds. It has a moon called Erinye.

Earth
Earth is the fourth planet from the Sun. It is one of two planets in the "Goldilocks zone" that enables the presence of life, as well as liquid water on the surface. It has one moon, the Moon itself.

Minerva
Minerva is the fifth planet from the Sun, and one of two habitable planets. It is about the same size as Mercury. Human colonization is banned by the Minerva Treaty of 1972, modelled after the Antarctica Treaty. Minerva has one moon, called Ariadne.

Hera
Hera is the sixth planet from the sun, and the smallest gas giant. Unlike the other gas giants, it has no rings or moons.

Erebus
Erebus is the furthest planet from the Sun, located well beyond the Kuiper Belt, and the largest gas giant. It is the most recently discovered planet, discovered and named in 2013 by El Kadsreian scientists. It has two moons, which have not yet been named.

Dwarf planets
There are 5 officially-recognized dwarf planets: Ceres (considered an asteroid before 2006), Pluto (considered a planet before 2006), Eris, Haumea, and Makemake.