Sol
Informally known as the Heart of Humanity, the Sol System is the most populous system in the modern Orion Spur and one of its most important. It is home to the capital of the Alliance, Unity Station. Untouched by the Solarian Civil War, the system was recently shocked by the Violet Dawn disaster of 2462. It was the first system colonized by modern humanity and has a number of colonies established on worlds without an existing atmosphere. Many Solarians from the Sol System refer to all spacecraft as rockets — a local slang term harkening back to the early days of space exploration, before the widespread adoption of terms such as spaceship and spacecraft.
Planets and Major Bodies
Mercury (Sol I)
Mercury is the nearest planet in orbit around Sol. It completes one full revolution around its parent star every 88 standard days, and has a day that is a little more than 58.6 standard days long. It is a small terrestrial planet, being smaller than Earth’s moon. Its surface is pitted with craters from eons of meteor impacts. The planet has a very thin exosphere composed mainly of oxygen, though it is much too thin to sustain any form of life. Mercury experiences wild variation in terms of surface temperature, with its daytime side reaching temperatures of 430 °C, and the night side dropping to the range of -180 °C. The planet faces constant bombardment from small meteors and solar wind, with no atmosphere thick enough to prevent it.
Mercury is home to a small population which resides in underground settlements — the surface being too hazardous — and staff the numerous power-generation facilities that cover the planet’s surface. Originally produced by the hegemonic-era Alliance, Mercury’s power generation network is known as the “Icarus Power Matrix,” and is now mostly owned and operated by Einstein Engines. Employees of the Matrix typically work six months on, six off, due to the planet’s hazardous nature. Permanent residents, called Mercurians, are rare but do exist, and are often remnants of the era when the government dominated Mercury’s industries.
Venus (Sol II)
Venus is the second terrestrial planet in the Sol system. A Venusian year lasts 225 standard days, while a Venusian day is longer, at 243 standard days. Venus spins retrograde when compared to the other planets in the Sol system, causing the sun to rise in the west and set in the east in its sky. Venus has an extremely thick and toxic atmosphere while its surface is an incredibly hostile environment.
Despite this, the upper atmosphere is known to be calm. All colonies on Venus take either the form of floating aerostats. While the temperature here is still a blistering 75C some of the aerostats, locally known as "donuts" due to their distinctive shape, tend to specialize in using the atmosphere's massive concentration of CO2 to cultivate extremely bountiful hydroponic farms, and Venus is one of the breadbaskets of the Sol System. Despite this, Venus is primarily known for its contributions to the Alliance's entertainment and media industry, and the planet is deeply divided between working-class Jintarians and richer Cythereans.
Earth (Sol III)
Earth is the third planet out from Sol. Earth has since regained its status as the jewel of humanity; it's central and arguably most important world. Earth is a Garden world, harboring millions of unique species of flora and fauna. It possesses extremely diverse ecosystems, with huge deserts, sprawling tundra, massive mountain ranges, rolling grasslands, and thick swaths of tropical rain forest. 71% of the Earth’s surface is covered in salt water while massive lakes of fresh water are found within continental areas. Humanity's home world is densely inhabited and every corner of the planet has a long, well-recorded history and culture.
Earth is home to a large but stable human and a small non-human population. The planet suffers from moderate space debris in high-orbit, a consequence of centuries of space travel. The Alliance maintains a significant naval presence around the planet. Earth has one moon, Luna, which has developed into a fully fledged member state of the Sol Alliance. Its residents are called Earthers.
Luna
Luna is the sole moon of Earth. It is tidally locked to its parent and makes a complete revolution every 28 standard days. It was formed when a rogue planetoid collided with Earth during the early stages of its formation. The moon came together from the resultant orbital debris. Luna was the first target of spacefaring humans as they pierced the outer layers of the atmosphere, and the first refuge of humanity as Earth was consumed by its climate crisis.
Luna is the oldest and most venerable of humanity's colonies, and is home to a vast amount of wealth thanks to the presence of megacorporations and those associated with their early successes. Lunans, despite being a relatively small population of slightly over a billion people, represent a disproportionate amount of the Alliance's naval officers and diplomatic corps. Luna is the headquarters and nerve center of Einstein Engines, the oldest of humanity's megacorporations and major rival of both NanoTrasen and the Stellar Corporate Conglomerate. Residents of Luna are typically called Lunarians, though many self-identify as Lunans instead.
Unity Station
Located in Earth’s orbit, Unity Station is the seat of the Alliance’s modern government. It was originally constructed after the Interstellar War when, in the wake of the Navy Coup, it was decided to move the government to a location theoretically outside of the territory of any singular member-state. Some, however, have long claimed the relocation was done by the Navy so they would be able to more easily threaten the government in another coup — after all, they would have no planet to retreat to. Alliance architects built Unity Station as a massive, pre-planned orbital colony station with the government located in its top levels — and the Senate at the very top — with residential and commercial levels below this, and docks at the bottom. One exception is the mid-level Interstellar War Memorial, which features the museum ship ASSNV Cincinnatus — flagship of renowned Interstellar War-era officer Commodore Gerhard von Varnhagen und Langenburg. The only surviving Beowulf-class dreadnought, the Cincinnatus was temporarily reactivated during the anti-Frost coup and used to force anti-coup forces to stand down.
Due to this design Unity Station has a permanent population, and is a member state of the Alliance which elects its own senators. Known as Stationers to others, the permanent residents of Unity Station are often Solarian government or military employees, and form a vast amount of the Solarian professional bureaucracy. Most are descended from either Earthers or Lunarians, with few originating outside the Sol System. Stationers are often stereotyped as colorless and humorless bureaucrats who care more for taxes than people, but they were among the first to participate in the anti-Frost coup, with many of the coup’s rank-and-file members being from Unity Station.
Mars (Sol IV)
Mars is the fourth planet out from Sol. A Martian day is only slightly longer than a standard day at 25 standard hours, but the Martian year is 687 standard days long. It is the outermost terrestrial planet in the Sol system. It is known as the Red Planet, because the iron-rich dust that covers most of the planet’s surface gives it a reddish tinge that was visible to the naked eyes of astronomers on Earth in ancient times. Mars had a thin atmosphere, but centuries of terraforming efforts have made it breathable. Mars was a target of one of the first bodies colonized by humanity. Its population swelled in the early days of the Second Space Age.
Mars has suffered two catastrophes while colonized: the abrupt failure of its terraforming infrastructure and widespread damage as a result of the First Interstellar War, when most of the planet attempted to secede from the Alliance. Mars is home to millions of descendants of refugees, cramped in centuries old bio domes or ruins. Yet Mars has proved resilient and today is one of the most populated worlds in human space with a highly advanced economy. Areas of the planet have been fully terraformed, allowing for massive, open air cities. These tend to be near the coastal areas.
The Violet Dawn catastrophe of 2462 and civil unrest in the weeks leading up to the catastrophe has seen Mars reduced to a shadow of its former self due to massive phoron fires that raged across the southern half of the planet and the utter collapse of government authority over the planet. Millions have fled the planet and dozens of arcologies have been destroyed, leaving the future of the planet uncertain. However, revitalization efforts by the Alliance and Einstein Engines have led to small improvements – but any significant recovery may take decades, if not centuries. Residents of Mars are known as Martians.
The Asteroid Belt
The Asteroid Belt is an area around Sol where thousands of rocky bodies, too small to be called planets or even dwarf planets, orbit. The zone encompasses an area between 2.2 AU and 3.2 AU away from Sol. The asteroids in the belt are rich in precious and semi-precious metals, hydrogen and water. The density of asteroids in the zone is relatively low, which was an important factor in allowing asteroid mining companies to establish footholds (BMC). The oldest and largest of these asteroid mining companies is the Beltway Mining Corporation, a rare independent corporation dating back to the 2100s, which has claimed the rights to mine most of the Asteroid Belt. Other fledgling companies have often been pushed out through strategic economic maneuvers, intimidation, and sometimes force. The Corporation has a main base located on the planetoid Ceres, the largest body in the asteroid belt. Over the years, the planetoid has been hollowed out by intensive mining operations, and now serves as a massive complex that the rest of their operations are based out of. The symbol of the BMC – a roc gripping a massive drill in its talons set against a golden, circular background – features prominently on many ships and outposts throughout the Belt.
Jupiter (Sol V)
Jupiter is the fifth planet out from Sol. It is the largest gas giant in the system and is actually two times larger than all the other planets of the Solar system combined. It is composed of Helium and Hydrogen in similar ratios as Sol itself, suggesting that Jupiter may have been on the road to becoming a dwarf star, but never achieved the mass to ignite. A Jovian day lasts approximately 10 standard hours, while a Jovian year is almost 11.9 standard years long. Jupiter is known for the multicolored bands and massive storms that are visible on the top of the planet’s atmosphere. The most well-known feature of Jupiter is its Great Red Spot, a massive hurricane many times the size of Earth that has been raging for centuries. Settlements on the gas giant are giant floating cities that grace the upper atmosphere, held aloft by massive, reinforced balloons. Jupiter has more than 67 moons in total, though only the Galilean Moons -- Europa, Ganymede, Io, Callisto -- are home to major settlements.
The Galilean Moons are major players in the Sol System: Callisto is one of the most densely populated bodies in the Orion Spur and serves as the Sol System's largest port, Ganymede produces a significant amount of the foodstuffs consumed in the System, and Europa is home to a great amount of scientific research facilities. Io, due to its inhospitable nature, features no permanent habitation. Residents of Jupiter are collectively known as Jovians, but generally refer to themselves by their moon of origin.
Saturn (Sol VI)
Saturn is the sixth planet of Sol, and the second largest gas giant in the system. It is known for the spectacular systems of rings that encircle the planet. It is the second largest gas giant in the system, with a composition similar to Jupiter. A day on Saturn lasts approximately 10.7 standard hours, while it takes almost 29 standard years for it to complete one full revolution around Sol. Saturn has more than 62 moons, most of them home to at least small settlements. With its hundreds of brilliant rings, Saturn is a major tourist attraction within the Solar system – Idris Incorporated offers many cruises around, and through, its rings. Like Jupiter, most of Saturn’s population is concentrated upon its moons. The largest population centers are Titan and Enceladus.
Enceladus
The most populated of Saturn’s moons, Enceladus was terraformed in a manner similar to Callisto by the Organization of American States (OAS) as a contrast to Pluto. Though originally intended to be a climate refuge for the residents of North and South America, the slow pace of its terraforming and relatively late time at which a Galatea Platform was available — in the 2250s, shortly after Callisto — combined with the start of the Second Great Depression in the 2260s led to the project becoming an Alliance-led venture in the later 23rd century, with the first colonists landing in 2287. In the decades since it has achieved success as a productive and prosperous, if unspecialized, Solarian world.
The residents of Enceladus are known as Enceladians, and can — despite the Alliance bailing out the OAS — mostly trace their origins back to North and South America, with the current residents carrying on much of their Earther traditions. Enceladians are said to be the closest one can get to Earth without visiting it, and many tourist traps constructed in “old Earth style” are found in its cities and towns. In recent years it has become a major destination for resettled Martian refugees, which has led to conflict with the local population. Unlike Earth and Mars, there is no great love — or unity — between the red planet and the moon.
Unique in the Sol System, Enceladus has a rotating capital which changes its city of location every five years.
Iapetus
A sparsely-populated closed moon of Saturn home to many government research outposts, Iapetus is most known for its unusual coloration and geography. The moon is divided between lightly-colored regions (Roncevaux and Saragossa Terra) and a darkly-colored one (Cassini Regio), providing a striking image from orbit and the planet’s nickname of the “Shrouded Moon.” Perhaps most striking is its massive equatorial ridge, known as the Shackleton Range, which rises as high as 20 kilometers into the air. It is the only moon in the Sol System where access is limited by the Solarian government, which requires a background check be performed on any potential visitors due to the moon’s many research labs. Longstanding rumors claim the Solarian government has black sites — clandestine research facilities and FTL-capable weapons of mass destruction— hidden in the Range, away from the eyes of the public, foreign powers, and the press.
Residents of Iapetus are known as Cassinians after Cassini Regio, where the moon’s population is concentrated. Most are employed by the Solarian government, which has long opposed private investment on the moon aside from limited facilities needed to support its permanent population. The Cassinians are a secretive and reserved people who tend to keep to themselves, and often come off as standoffish. They have long formed a significant part of the Solarian security apparatus, with many SIIB officers originating from the shrouded moon. A popular Solarian joke claims a Cassinian and the similarly reserved Visegradi placed in the same room can go for months without saying a word to one another.
Iapetus’ capital is Lamures, located in the Cassini Regio. The capital derives its name from a Roman term for the restless dead, and has been taken by some as a jab by the population towards their reputation as a black site.
Uranus (Sol VII)
Uranus is the seventh planet of Sol. It is an ice giant that is tilted on its side so that its equator is at a right angle to its orbit. A day on Uranus lasts approximately 17 standard hours, while its orbital period is approximately 84 standard years long. The planet has 27 moons, with most of them holding small outposts.
Uranus, like Neptune, is home to a significant Solarian Navy presence. The Navy’s main mothballing facility is located in its orbit, and a staged attack on it was used by Michael Frost to help his seizure of power. Its population is concentrated on Titania.
Titania
The largest moon of Uranus, Titania has a sparsely-populated surface with most of its population living in orbital stations — many lacking conventional artificial gravity technology due to their age. The moon’s surface is home to enormous canyons and ravines in addition to deposits of water ice and frozen carbon dioxide. While a candidate for terraforming in the 22nd century, it was passed by in favor of Callisto and the population has long lived in orbit. This has made Titania the largest offworlder human population in the Sol System — potentially in the entire Alliance — and made the population regarded as exceptional orbital engineers. It is sometimes referred to as the “cradle of off-world humanity” as the adaptations were first observed here.
The residents are known as the Titanii, but are often called “Titans” due to their tall stature. Most are employed in the Solarian Navy’s facilities in Uranus’ orbit, and are valued by the Navy for their natural adaptation to low-or-no-gravity environments such as ships undergoing construction (or deconstruction) in orbit. Their orbital stations are some of the largest and best-maintained in the modern Spur, and Titanii engineers were heavily involved in the construction of Unity Station. Titania is one of the few places in the Alliance offworlders immigrate to, with offworlders from as far away as Burzsia or Empyrean settling in its stations.
The capital of Titania is Lysander Station, the largest of the stations in orbit. It takes its name from the same source as the moon: A Midsummer Night’s Dream.
Neptune (Sol VIII)
Neptune is the eighth planet of Sol, and the sister ice giant to Uranus. It has a very similar composition, with high amounts of methane present in the atmosphere. Large amounts of water are also present in the planet’s mantle. A Neptunian day lasts approximately 16 standard hours, while a Neptunian year is 165 standard years long. Neptune has 17 moons.
Perhaps appropriately for a planet named after a god of the seas, Neptune has long been dominated by the Solarian Navy.
Triton
Neptune’s largest moon, Triton is a young and geologically active world covered in ice and fissures. Despite its thin atmosphere impact craters are rare due to the constantly-shifting surface of the planet, a phenomena which occasionally gives rise to spectacular cryovolvanic eruptions that shoot kilometers into the Tritonian sky. Habitation of its surface is dangerous at even the best times, and the population lives in ring-shaped orbital stations that orbit the moon.
Tritonians — residents of the moon — are typically employed in Neptune’s naval yards, where everything from corvettes to the gargantuan Thule-class supercarriers of the Navy are produced. Many Tritonians worked for Hephaestus Industries prior to 2462, though most of these facilities have since been seized by the government or bought out by Einstein Engines. They will proudly brag they are the greatest interstellar engineers in the modern Spur, and many Solarian deep space salvage and construction companies employ Tritonians.
The capital of Triton is Voyager Station.
Pluto (Sol IX)
Pluto is the ninth planet in the Sol System, and one of the furthest permanently inhabited bodies from the Sun. It maintains an unusual local political and economic system as a result of its colonization by the USSR during the 2100s, and serves as the primary Helium-3 mining and refining area for the Sol System -- if not the entire Solarian Alliance.
Eris and Dysnomia
The furthest bodies in the Sol System with major, permanent populations, Eris and its moon are home to Solarian Navy facilities, deep-space research centers, and the Sol System’s largest interstellar communications arrays. Subsurface oceans cover Eris, which has complicated construction on the planetoid and led to most of its population living in aboveground domes connected by underground rail lines, and relying on atmospheric shield generators to keep them safe. As a result, Eris has a very high population density — domes cannot be easily expanded, and it is often easier to build up (or down) than out. Eris and Dysnomia were the last bodies to be colonized in the Sol System — with the first colonists landing in 2209 — and is one of the only non-moons not considered a planet, despite it being larger than Pluto. The surface of Eris is covered in highly volatile methane ice and reaches temperatures as low as -217 Celsius, making activity hazardous for all but the well-trained.
Residents of Eris are known as the Erisians, and are taller and paler than most humans due to the lower gravity of their home and its distance from the Sun. This, combined with their preference for careers in the Navy, has given the Erii the nickname of “Little Lunans” in the Alliance — a nickname many from the planetoid and its moon are not appreciative of. Their small world and high population density has made the Erii into a social culture where close connections are deeply valued, and an Erii is said to be as good as their word. Most Erii work in the scientific or interstellar communication fields if they do not join the Navy. Due to their distance from the sun, many Erii suffer from sunlight sensitivity and the local government has long freely distributed vitamin D supplements.
Eris and Dysnomia’s status as an interstellar communications hub led to it being seized by anti-Frost elements — led by its governor — during the 2462 coup against his government. Military forces stationed on it after this worked to nationalize corporate-owned equipment on the planet, leading to an economic downturn the twin worlds have only recently recovered from through government investment and both Idris Incorporated and Einstein Engines having bought up much of the property seized from other corporations. Almost every communication to or from the Sol System — from Sol Alliance News Network broadcasts to Chirper messages — flows through here, and business has only increased with the end of the civil war.
The planetary capital of Eris and Dysnomia is Discordia, Eris’ equivalent in Ancient Rome.
Other Trans-Plutonian Objects
A collection of dwarf planets beyond the orbit of Pluto collectively known as TPOs, these objects — aside from Eris and Dysnomia — have no permanent residents and are mostly owned by the Solarian Navy, which operates naval outposts and deep-space listening arrays on them. Some of the most notable are Sedna Station — a central hub of Navy activity in the distant region of Sol known as the Scattered Disc, Gonggong Station — a deep-space listening array, Leleākūhonua Station — another deep-space array, and Leng Station — the furthest Solarian Navy garrison in the Sol System. Informally known as the “last stop” by the Navy, Leng Station is regarded as one of the worst postings in the Sol System due to its remoteness and near-constant darkness.
The Kuiper Belt
The Kuiper Belt is the region beyond the orbit of Neptune that is home to tens of thousands of icy bodies, and potentially hundreds of thousands more. The Kuiper Belt encompasses an area from 30 AU to 55 AU away from Sol. Of the icy bodies present in the belt, Pluto and Eris are the most well known. The icy bodies here are rich in hydrogen and water, but lacking in terms of other resources aside from Helium-3, such as metals. The Kuiper Belt may be home to billions of comets too small to be detected.
The Oort Cloud
The Oort Cloud is a spherical area of space that encases the Sol system. It begins where the Kuiper Belt ends, and extends outward until almost 1.5 LY away from Sol. It is estimated that Oort Cloud may contain up to a trillion icy bodies, including planetoids and comets. Unlike the Romanovich Cloud of Tau Ceti, the bodies in the Oort cloud are metal-deficient, leading to limited mining aside from Helium-3 harvesting.