Sol System

## Overview

The Sol System, colloquially known as the Solar System, is the origin of humanity and the capital of the Federated Planets of Earth (FPE). As the birthplace of human civilisation, Sol is a living testament to human achievements, including the formation of the first unified global government, the colonization of Luna (Sol llIa), the terraforming of Mars (Sol IV), and the erection of Sol Station, the largest human-engineered space station until 2500, second only to Alexandria Citadel.

The majority of space-based infrastructure can be found in the Herschel and Kuiper Belt's and around the four gas giants, where centuries of mining operations have allowed Sol to develop dozens of highly developed colonies across the system.

The inner system remains the busiest and most technologically advanced region within the FPE, with it's capital of Earth (Sol III) boasting a population of over 12 billion individuals and one of the largest GDP's in the known Milky Way. Furthermore, a large portion of the Federal Military is drydocked in low Earth and Mars orbits while a strike fleet known as the 1st Strike Force is permanently stationed at Sol Station.

## History

The Sol System was formed about 4.6 billion years ago from the gravitational collapse of a giant molecular cloud. The vast majority of the system's mass is in the Sun, with the majority of the remaining mass contained in Jupiter. The remaining mass was distributed among the outer gas giants and inner rocky planets, forming Earth, and hence spurring the development of humankind. Throughout humanity's development on Earth, Sol remained largely untouched until they entered the space age in the mid 20th century during the Apollo missions. While progress was slow through the late and early 21st centuries, with humanity being confined to low Earth orbit, the 2020's and 30's saw the rapid exploration and colonization of the Sol System, accelerating exponentially into the 22nd century witht the The subsequent centuries saw the complete terraforming of Mars and the significant colonization of several Jovian and Saturnian moons, transforming the Sol System from a single-habitable-planet system to a cradle of human life and civilization.

## Gravitational Governors

### Sol (G2V Main Sequence)

The Sun also known as Sol is a G-Type Main-Sequence star (G2V), informally known as a yellow dwarf, at the centre of the Sol System. It was formed approximately 4.6 billion years ago and is situated in the Orion Spur, a partial arm located between the Sagittarius and Perseus arms, orbiting the galactic centre at a distant of 26,660 light-years.

## Planets

### Mercury (Warm Airless Subferria)

The smallest and closest planet to the Sun. Due to its proximity to the Sun, it has extreme temperature variations and no atmosphere to speak of, making it unhabitable without the assistance of technology. Nevertheless, human civilisation has endured, and Mercury is home to a large population, primarily producing raw materials and alloys.

### Venus (Hot Arid Terra)

The second planet from the Sun, known for its harsh, greenhouse gas-filled atmosphere, Venus is currently undergoing gradual terraforming efforts to make it habitable and is populated by approximately one million people in helium-based floating colonies.

### Earth (Temperate Marine Terra with Life)

The third planet from the Sun and the only planet in the Sol system to naturally support life, Earth is the cradle of humanity and the capital of the Federated Planets of Earth (FPE). Today, the planet is a vital hub for interstellar politics, trade, and cultural exchange. Known for its diverse ecosystems, vibrant cultures, and storied history, Earth has a population of over 12 billion people and is one of the most prominent planets in the Inner Orion Spur and the wider Milky Way.

### Mars (Cool Marine Subterra With Life)

The fourth planet from the Sun, Mars is known for its ambitious terraforming efforts, rapid population growth, and position as a frontier for human exploration and expansion. First settled on July 6, 2031, Mars has undergone a remarkable transformation, developing a breathable atmosphere, liquid oceans, and burgeoning plant life. In the 23rd century, Mars is home to 4.8 billion people and serves as a shining example of human ingenuity and adaptability.

#### Moons

* Phobos (Cool Asteroid)
* Deimos (Cool Asteroid)

### Ceres (Cold Airless Microterra)

Located in the asteroid belt between Mars and Jupiter, Ceres is the largest object in the Herschel Belt and is classified as a dwarf planet. It's primarily mined for ice to sustain terraforming efforts across the system.

### Jupiter (Cold Jupiter)

The fifth planet from the Sun and the largest in the Sol System, Jupiter is a gas giant with a multitude of moons, some of which support human colonies, one of which, Europa, was the first place that life was identified by humanity beyond Earth.

#### Moons

* Io (Cold Airless Miniterra)
* Europa (Cold Airless Miniaquaria with Life)
* Ganymede Cold Airless Subaquaria)
* Callisto Cold Airless Miniaquaria)

### Saturn (Cold Subjupiter)

The sixth planet from the Sun, it is recognized by its prominent ring system. Saturn's moon Titan is home to a thriving human colony.

#### Moons

* Mimas (Frigid Airless Microaquaria)
* Enceladus (Frigid Airless Microaquaria with Life)
* Tethys (Frigid Airless Microaquaria)
* Dione (Frigid Airless Microaquaria)
* Rhea (Frigid Airless Microaquaria)
* Titan (Cold Lacustrine Subaquaria)
* Iapetus (Frigid Airless Microaquaria)

### Uranus (Frigid Neptune)

The seventh planet from the Sun, it's an ice giant known for its blue-green color due to methane in its atmosphere. Uranus remains largely uncolonized due to its inhospitable environment, however is home to several large scale mining operations.

#### Moons

* Miranda (Frigid Airless Microaquaria)
* Ariel (Frigid Airless Microaquaria)
* Umbriel (Frigid Airless Microaquaria)
* Titania (Frigid Airless Microaquaria)
* Oberon (Frigid Airless Microaquaria)

### Neptune (Frigid Neptune)

The eighth and farthest known planet from the Sun in the Sol System. It is another ice giant similar to Uranus, notable for its deep-blue appearance.

#### Moons

* Proteus (Frigid Asteroid)
* Triton (Frigid Arid Microaquaria)

### Pluto (Frigid Arid Microaquaria)

Once considered the ninth planet from the Sun, Pluto was reclassified as a dwarf planet in 2006. Due to its remoteness, even in the 23rd century it only sustains a small population, mostly centred around the Seager Observatory Complex.

### Eris (Frigid Airless Miniaquaria)

Discovered in 2005, Eris is a trans-Neptunian dwarf planet, and it's the most massive dwarf planet in the Sol System.

## Asteroid Belts

### The Herschel Belt

The main asteroid belt (also known as the Herschel Belt), located between Mars and Jupiter, has been a significant location for mining operations due to the abundance of metals and water ice.

### The Kuiper Belt

The Kuiper Belt, beyond the orbit of Neptune, is home to several dwarf planets and is a frontier for exploration and resource extraction in the 23rd century.

## Space Stations and Megastructures

### Sol Station

Located around the Sun is the most iconic is Sol Station, the largest human-made space station which kickstarted humanity's 'Outpost Program' and a central hub for interplanetary commerce, governance and the majority of the Federal Military's Sol-based fleets.

### Sol Dyson Swarm

The Dyson Swarms around the Sun capture solar energy for the system's increasing needs.

### Alexandria Citadel

Among the most iconic stations in the system and Sol's first 'megastructure' is the "Alexandria Citadel", a massive repository of all human-accrued knowledge located in Earth's orbit.

### Unity Station

Sharing Earth's orbit is "Unity Station", a massive Stanford Torus Ring housing the Federal Military, aspects of Earth's local governments and over 160,000 people.

### Ares Station

Mars hosts "Ares Station", a pivotal hub for interplanetary travel and commerce.