As far as stars go, Eos numbers among the smallest in Cosmoria. At just 200,000 km across, its habitable zone lies a mere two million kilometers from its surface. Under normal circumstances, this star would have a population somewhere in the billions, a mote on the scale of Cosmoria's civilizations. Eos, however, is not a typical star, for surrounding it is a megastructure dwarfing all others. This massive construction is a large flat disk orbiting this dwarf star. On it resides 9 trillion, environments unseen anywhere else, and some of the most influential empires in history.

Eos is the gateway to Aylathiya from elsewhere, lying in the center of Martial Space. An economic powerhouse: merchants, companies, and governments often use the large structure as a staging ground for commerce of all kinds. Underneath the trade-friendly orderly surface is an eternal conflict as dozens of factions strive to exploit Eos' lucrative position. A gilded world, the guise only occasionally disappears. When it does disappear, however, it disappears with great force, leaving the rest of Cosmoria suffering generation-defining recessions.

Nearly every group imaginable takes credit for the creation of Eos, from the Dotsk who have a reputation for building megastructures, to nationalists in Florathel that claim only the Lareas Alliance could have created the structure. Historians on Eos sometimes credit its creation to Cosmic Commonwealth of Mages, but the consensus is that Hyperion built it. Regardless of the origin, it has continually existed for essentially all of recorded history, likely taking much of this time to construct. It is technically unfinished, as a large section remains unfilled.

The world remained a disunited backwater on the galactic stage until the rise of the Triumvirate Civilization 40,000 years before the present day. This civilization's meteoric rise caused Eos' population to balloon to over 20 trillion by 80,000 CE. When the Triumvirate fractured as its three leaders went their separate ways, the resulting war caused its population to dip below one trillion, resulting in a galactic recession that has still technically not ended. From then, Eos has continually united and fractured until the modern day, currently existing mostly united under the Greater Martial Consilium.

History

Pre-History

The Eos system formed shortly after the emergence of Cosmoria 6.2 billion years before the present day. One of Cosmoria's lightest stars, Eos was a red dwarf with as many as five planets under its sway. The system was likely very compact, stretching at most seven million kilometers from the star's surface. The star likely never hosted native life.

Pre-Antiquity

Eos is about 120,000 years old, making it by far the oldest extant megastructure in Cosmoria. The original disk, a thin band of living area scarcely one thousand kilometers wide, was a fundamentally different megastructure. With gravity powered by rotation and the liveable area facing the central star, this ancient ring had about a millionth of its current surface area. While its name was lost to time, this early disk hosted the ancient Hyperians, the first to achieve lasting civilization in Aylathiya.

Construction

Colonization by Ma'eau

Fall

Ancient History

Foundations

Paradigm was the first modern city on Eos. Then called R'Yvv, Paradigm represented the entirety of civilization in Aylathiya. Its founding Naidarans fought countless wars with native Kristals over its territory. Neither species saw the other as intelligent and, without modern decoding techniques, communication was impossible. In 20,000 BCE, Kristals represented the vast majority of the population. Minorities, such as Naidarans and Lorsavt, each accounted for ten percent. During this era, Paradigm rose and fell three times. The Kristals nearly annihilated the Naidarans on a handful of occasions. Every century, a "Hero" emerged amongst the Naidarans who drove back the hoards of Kristals. Ancient murals and slabs describe heroes as "cold to the touch," "invulnerable," and "holders of lightning." These impressive abilities suggest the first known use of Invocative Thaumaturgy.

The Civese were an ultra-rare species that only recently evolved intelligence. Occupying less than a hundred square kilometers of space, less than three hundred calls Eos home. As they slowly unlocked agriculture, their population increased by thousands of times. They resided near the modern site of Civestadt. Another primitive species, the Arkhosians, originated on Sakijast, Lycurgus, only to have traveled to Eos many millennia prior. Unrecognizable from their original state, they remained in isolated villages during this period. The Atlins remained primitive throughout this period. Made of plasma, it was difficult for them to break out of their ecological niche.

Eos remained devoid of technological civilization. As the millennia went by, heroes lived and died, villagers congregated and scattered, and monuments rose and fell. In a small number of cases, something approximating technological advancement formed. Seven hundred years after Paradigm's founding, its people developed the ultimate cultural advancement, the ability for anyone to practice Invocative Thaumaturgy. The ancient hero, Director C'Tealkalich, spread his abilities amongst his fellow Naidarans. At once, they pushed back most Kristals. While never quite uniting Eos, they became its dominant power by 19,750 BCE. By then, they called themselves the Cosmic Commonwealth of Magi.

A small wave of refugees landed on Eos in 19,875 CE. Fleeing the collapse of Karith the Accursed's empire, the Carlean refugees numbered only one thousand. Most did not make the perilous journey this deep into Aylathiya, let alone the ancient megastructure in its center. Eleven further waves brought the Carlean population to 100,000. Despite bringing advanced technology, they lacked the extensive port infrastructure to repair their crashed ships. Carlean civilization depended on what little industry they brought with them. 3D printers and solar forges represented the bulk of their technology. After just a century, their civilizations decayed beyond functioning.

The Kristals nearly destroyed all Carlean settlements; were it not for the intervention of the Cosmic Commonwealth, they would have gone extinct after only 150 years. Communication was slow, but rough approximations of sounds were sufficient. While a handful of the original refugees were alive, most were born on Eos and thus gave an inaccurate account of their time in space. Tales of deities, mountain-eating monsters, and "people beyond the sky" became even more embellished due to analogies, metaphors, and untranslatable words. The Commonwealth immediately attempted to investigate their stories. However, without the requisite technological development, they were trapped on their home.

After further centuries, the Commonwealth's most devoted Magi would elevate to the status of Paladin. This ultra-devoted devotee sat at the apex of Invocative Thaumaturgy. These Paladins wielded tremendous power that surpassed that of even the ancient heroes. For the first time, Naidarans gained the upper hand in the perpetual war against the Kristals. Like removing a predator from an ecosystem, Naidarans, Civese, Carlean, and Lorsavt populations greatly increased.

Leaving the Surface

The Cosmic Commonwealth perfected space travel nearly a millennium after it was founded. The first form of space flight, space planes, allowed for travel to anywhere on Eos within three weeks. Large boosters brought the plane to the correct height only for it to glide for most of the journey. Most of these trips were one-way. Further advances allowed for them to remain airborne throughout the whole trip, cheapening cost but requiring cargo to be ejected from high in the air. Colonies on the far side of the disk were easy to keep in line; any wavering in loyalty would mean cutting off resource deliveries. The first challenge was making them profitable. It was difficult to return resources over reasonable periods.

Given Eos' high escape velocity, it took very long to escape it altogether. The first Naidarans to leave spent weeks in orbit. Climbing even higher, to Eos' satellites, yielded little. The first, Albedo, was a barren wasteland of glaciers punctuated by small oases of volcanic activity. Hikari and Eosphoros were no better; both worlds barely clung to toxic atmospheres. Interstellar travel was still out of the question. With population growth leveling and increasing automation, the drive to expand dwindled. Eos was effectively infinite, held all the resources a civilization could need, and was rapidly developing.

The Commonwealth found the needed motivation in 16,985 CE when Dotsk explorers landed on Eos. Unlike previous species, however, they did not leave behind a settlement. The Dotsk were far ahead of any civilization on Eos, but there was one thing that it had that they wanted. Resolute Bronze is an ultra-strong alloy that makes up the bulk of Eos. This material makes up even soil infill, making it a valuable resource. The Dotsk homeland, called The Array, desired a strong ally and thus began trading for the material. By 15,000 BCE, the Dotsk figured out how to synthesize the valuable material, but Eos now had technological parity with them. Commonwealth envoys explored all of Cosmoria, importing promising paladins from throughout. Already in the cosmopolitan world, Eos' diversity only increased. R'Yvv, now called Zero'Yvv, had a population of 50 billion and over twelve different species.

The Overlords

An Overlord is a being of immense power that qualifies as a civilization in its own right. Whether an ultra-powerful Magi, an artificial superintelligence, or a hivemind organism, these singletons act as individuals on the galactic stage. The Commonwealth observed several naturally occurring Overlords, such as Laborosoarchod. At first, they thought little of these ultra-powerful entities. The unrivaled paladin army was thought to be invincible. In truth, the army was effectively invincible. Over one billion of the finest paladins in the universe, led by generals of legendary devotion called Saints, were impossible to destroy from the outside.

The fall came from within. The strongest saint at the time, H'Araimaluk, discovered a new form of Thaumaturgy, now called Meridian Thaumaturgy. This practice is slightly different from Invocative Thaumaturgy; it is centered on devotion to an intelligent being rather than a concept. H'Araimaluk abandoned the Commonwealth to focus on what he called The Orrery God. After offering his god every state secret, a power struggle emerged amongst saints seeking to replace him. The resulting civil conflict tore apart the Commonwealth's large army, plunging Eos into chaos.

Physical

Embedded within Eos is a large mechanical apparatus of fractal complexity. The task of maintaining the disk against tidal forces, asteroid impacts, opportunists looking to harvest its materials, and other degradation, requires more energy than the remarkably small star can provide. Eos has an entire ecosystem within and around it that serves to maintain its structural integrity. Powering this ecosystem is a vast sister structure located around the nearby star of Gira Gira. Called Phaethon, the system has successfully defended it for longer than modern civilization has existed.

Structure

Eos is composed of Resolute Bronze, a gold-brown-colored alloy widely renowned for its material strength. Structures like Eos have a maximum theoretical radius of over four million kilometers. Eos has a radius of three million kilometers and a surface area equal to 25 trillion square kilometers. Embedded within this structure are a series of large orbital rings with a thickness of, on average, 1150 kilometers. Within them, small charged black holes race around the star at relativistic speeds, their momentum canceling the force of gravity that would otherwise collapse the disk.

Eos is not quite flat; it gently angles upwards at 0.01% grade. The resulting bowl shape keeps gravity uniform and air contained. Were it perfectly flat, gravity would pull towards the center, straining the orbital rings and making life impossible on its surface. The structure thickens as the distance to the star increases. Small variations in the thickness results in mountains, lakes, flats, and oceans. Overall, Eos is very smooth.

Climatic Regions

The Icaran Ring

A mere one million kilometers away from its star lies in the innermost region of Eos. Carbon-based life of any kind cannot last long in these hellish conditions. Water becomes mist within moments. In this region, seas of molten lead are commonplace, with an entire ecosystem of this lead-based life inhabiting its seas. As the lead evaporates, at a slow rate given how close it is to its melting point, the toxic clouds interact with Eos' oxygen-rich atmosphere, creating particles of lead oxide that can travel far across the disk. Drifts of the snow-like substance are common much farther in, but if they fall back into the Icaran Ring, they will degrade into liquid lead once more.

Silicon dominates the soil of this region, and most carbon quickly becomes carbon dioxide under these conditions. The occasional solar flare from the star can liquefy large portions of the soil, leaving in its wake large fields of quartz crystals that can stretch for thousands of kilometers. The other structures to break up the flat landscape are massive wind turbines, capable of converting the powerful wind currents of Eos into energy. Winds in the Icaran Ring rarely drop below 50 kilometers per hour, requiring life such as the Atlins to seek shelter in caves or behind large walls. The air is choked with smog, particulates, and other impurities, while also having nearly twice the pressure as it does towards the edge of the disk.

For the past 50,000 years, large mirrors have existed above Eos to concentrate light onto Orcubor settlements, creating regions of over 2000 degrees Celsius. These hellish regions threaten the very structural integrity of the disk, requiring extensive cooling systems maintained by various governments. The most extreme of Cosmoria's life, aluminum-based creatures made of liquid quartz, inhabit these furnace-like conditions.

The Hadean Ring

Further out lies an area that is too hot for liquid water to exist but too cold for seas of lead. The only life in this area are organisms capable of weathering its barren flats. Dotted by the occasional oasis, not of water but of gallium metal, clouds of any sort are rare. Interaction with air and water vapor from further out causes the gallium to oxidize, creating a thin crust above the lakes of metal. Low-energy ecosystems exist in these rare oases.

Life from D'Naevium is perfectly adapted to this environment and exists in isolated communities around the gallium deposits. The animals learned to punch through the thin sheets to drink. They also became far more resistant to wounds. Their injuriesare self-cauterizing since their gallium blood immediately hardens. With ferocious abandon, the largest predators know no fear, throwing themselves at anything they can. Vehicles passing through the region are prime targets.

Far from the pools of gallium, the only thing to disrupt the landscape is train tracks, wreckage from an untold number of battles, scavengers, and autonomous machines poking through the igneous soil. Large fields of solar panels power remote facilities and factories. The occasional settlement, pressurized like a space station for every species except Ror Units, is usually near the rail lines. The atmosphere is pure compared to the Icaran Ring, but still not healthy to breathe.

The Common Ring

The Common Ring is the largest by area and the most heavily populated. Beginning two million kilometers from Eos, vast seas dominate the ring. Remnants of an ancient molecular nebula explain where the resources for the oceans came from. From the nearly-boiling seas of the interior to the periodically frozen seas of the edge, the Common Ring hosts life of all sorts.

As one moves from the center of the ring to the edge, the variation in the surface increases. By the Common Ring, large mountain ranges and valleys dominate the landscape. As for visual variety, the Common Ring reigns supreme as vast forests cover much of it. Forests battle against the massive carbon dioxide production of not just the Icaran Ring but the intense industry of its inhabitants. If a species is carbon-based and can tolerate water, chances are that a population lives in the Common Ring. The interaction between trillions of bacterial species creates a unique ecosystem in which nearly all lifeforms can survive.

Despite its favorable conditions, cities represent less than a percent of the Common Ring. Its sheer size means that urban areas account for less than a percent of a percent of its surface. The space between major settlements is truly untamed wildernesses punctured only by the occasional village, of which there are many. The Common Ring contains over 4 million settlements with more than 100 inhabitants. Like the stars in the skies above them, vast distances separate the settlements. Nearly half of them remain uncontacted.

The Boreal Ring

The Boreal Ring, named for the Boreal Anemoi Company and the Boreal Empire that replaced it, is the newest region as well as the coldest. The innermost area allows for liquid water for brief portions of the year, but most water remains frozen. Lightly populated, the region is nonetheless home to large amounts of energy-intensive industries such as element synthesis and asteroid refinery. These islands of heat in the otherwise frozen wasteland create wet urban environments. Straying too far from these cities leaves one in endless snowbanks.

Rail in the Boreal Ring is limited to large freight trains that occasionally have areas reserved for passengers. They can operate on cold superconductors, allowing for cheaper construction and operation. The newest and largest space ports on Eos can be found in the Boreal Ring. The byproducts from the constant use of rocket engines, industry, and other activities create toxic pools that would evaporate or break down at higher temperatures.

Seasonal Climate

Eos has had a substantial wobble for all of recorded history. If the star were stationary, this would create little to no variance; however, the star effectively orbits the "barycenter" it shares with the disk. This orbit creates a bobbing motion that results in days and nights on the megastructure. Combined with the disk's wobbling, there are periods, called "Eos Years" over which the portions of the disk receive more or less sunlight. Additionally, in the coolest part of the year, sunlight is much less direct. The seasonal climate matters far less in the blazing Icaran Ring than it does in the frigid Boreal Ring. At the farthest reaches of the disk, the variation becomes extreme, varying by over 200 degrees Celsius (about -200 to a little below freezing).

Influence by nearby stars and planets also causes the disk to flex slightly. This flexing and relaxing takes place over six hundred years and is again most influential for the Boreal region. It changes how much sunlight an area is exposed to during the "summer" periods, leading to the Boreal Region sometimes flowering in rare events called "Vernal Events," attracting tourism but also inhibiting industry.

Orbiting Bodies

Eos, in particular the disk-star barycenter, is a massive object and thus possesses several orbiting bodies. There is evidence of a heavily depleted asteroid belt that once existed around the star that may have supplied a portion of the material that makes up Eos. In addition to natural bodies, there are gigatons of material placed into orbit around the body every year; much of it has become space junk. The oldest material orbiting Eos dates back over five million years.

Albedo

Albedo is the most massive natural satellite of Eos. It seems to have been left alone during the construction of the disk. Albedo orbits at 5.1 million kilometers from the star. Its orbit is inclined by 17 degrees relative to the disk as well. It is the brightest object in the night skies of Eos due to its incredibly high albedo for which it was named. Consequently, it is very cold on this world. It is covered in a layer of ice; however, islands of thriving ecosystems exist in volcanic regions. Geothermal energy heats most of the planet's cities. It was the first world colonized by Humans outside their home system.

Hikari

Hikari orbits at about 6.5 million kilometers. The planet has a very low surface gravity and density, resulting in a very small poulation. By mass, it is over twenty-five percent copper. Most scientists believe the planet is a byproduct of Eos' construction. Its inhabitants have been slowly eating away at the planet, converting it into raw materials. Much of the planet has fueled the industries in the Boreal Ring.

Eosphoros

Eosphoros is a large terrestrial planet located 10 million kilometers from the star. A Hedonist World, Eosphoros is home to a large number of ruins from the ancient Second Aeternal Society. Its ancient guardians have never allowed an external nation, save for the Triumvirate Civilization, to conquer it. Eosphoros has a thick atmosphere and rich geothermal activity that keeps it warm. It seems to have no intelligent life, its inhabitants having evolved into beasts of all kinds, including Aeternapes.

Dark Side of Eos

Reverse the highly populated side of the disk is a sparsely populated region poetically called the "dark side." Without much in the way of ground to stand on, jagged struts, beams, and pillars are the only solid surface. Eos' defense systems prevent any intrusion deeper than 20 kilometers. The defense of choice is electrical discharges, vaporizing any that dare trespass upon the disk's inner workings. A handful of facilities take advantage of this system, gathering a great amount of energy in the process. While out of the way, the power in this area is cheap and thus sustains a handful of energy-intensive industries. Most of these facilities are pressurized as the air on this side is thin and toxic.

Composition

Beyond the internal structure of resolute bronze, Eos is composed of whichever substance was cheapest for the civilization building the section. Some areas are composed of lithium and beryllium, suggesting a civilization capable of large-scale fusion without much use for these materials. Many areas are composed of heavier metals; asteroids often fed 3D printers. Silicates are common as well. There is evidence that entire planets have been used as feedstock for some of the oldest areas.

The most recently built areas, built by the Dominion of Astraeus, are composed of an iron-silicate mixture. It was created by importing energy from Sagittarium to turn an orbiting dwarf planet, Aura, into raw materials. While most of the disk is solid, filled with an ultra-low-density substance that maintains rigidity despite being mostly vacuum, many of the newest areas have yet to have been filled in, creating a slightly diagonal pull of gravity in those regions.

Biosphere

Across Eos, there exist thousands of unique biomes, ecosystems, and organisms. Life from throughout Cosmoria, even from as far as Florathel, have colonized Eos. The biosphere occupies nearly all of Eos, including the space around it, which hosts large amounts of Spaceborne Life, and vacuum-tolerant microbes that reside within its interior. The vast majority of biomass exists on Eos' surface, in particular in the Common Ring. It accounts for slightly under 90% of its total biomass. Consequently, water-based life is the most common life on Eos.

Ma'eau created most of the life on Eos, the species developed to fulfill specific roles. The entity is deeply embedded into Eos' biosphere and works constantly to maintain its fragile balance. Other forms of life, such as life from D'Naevium, remain isolated and thus rarely interacts with most other life.

Marred Regions

A Marred Region is a region of Eos created by Ma'eau during its mental dissociation. Often called "Ma'eau's Civil War," numerous competing wills within it warred against one another. During this period, Ma'eau had a difficult time creating new organisms or guiding their evolution, leading to an increase in genetic diversity or the propagation of undesirable mutations.

Standing in a marred region, one would usually see little of note. In the majority of these areas, bizarre microbes reduced the soil into a slurry of acidic compounds, resulting in a muddy wasteland punctuated by the occasional pool of acid. Deeper into these ecosystems, where these microbes act as the basis of the ecosystem, one would have hardly anywhere to stand. In most of these regions, deep pools of sulfuric acid create swamp-like conditions throughout much of the biome.

Phaethon

Maintaing Eos requires far more energy than the small star could ever hope to provide. While drawing energy from the star is practiced in the innermost regions, most areas require imported energy. Without robust supply chains that can provide all the needed antimatter, the industry on Eos crawls to a halt. Those who built Eos were also aware of this glaring problem; the disk required nearly ten times more energy than Eos can provide to stay together.

This is where Phaethon comes in, the system that powers Eos. A decentralized network unrivaled in complexity, Phaethon tirelessly works to maintain the orbital rings and the infrastructure powering them. The construct has been demonstrated to be somewhat intelligent. Occasionally, its drones will find asteroids or other material to repair Eos, always careful to never take anything artificial.

Phaethon has two twin rings, the outermost ring of Eos and a much larger rotating ring orbiting within Gira Gira's atmosphere. The ring around Gira Gira gathers and remotely transmits power to the ring on Eos. There are numerous underground factories on Gira Gira's largest planet, Taek, which are most likely responsible for creating the various craft Phaethon commands. The factories are nearly entirely mechanical, with few electronic devices present. A central line shaft is responsible for the power supplied to machine. Phaethon's drones frequent Taek, but none have ever observed the factory running.

The drones derive power from the gradual unwinding of a spring. It is unclear how they power their sensors or even how they are capable of such complex actions as they are each made up of billions to trillions of often microscopic gears. They contain thousands of smaller machines responsible for internal maintenance. Their springs need to be rewound every so often, likely at substations similar to the main factory. They are made up of the same tungsten-titanium alloy as the ring. They often grab onto departing craft or climb tall structures to leave the disk.

On Eos, capturing or otherwise interfering with these drones, even if they cause property damage, is a capital offense. This is obviously to protect the structural integrity of the structure but to also learn about them. There are most likely several factories or substations located within Eos, but internal exploration of the disk is impossible. Boring into Eos is incredibly difficult, Phaethon usually forcibly stops any who try by sending strong electromagnetic pulses at the offending borers. Thus, Phaethon's structure has been shrouded in mystery, the construct doing everything it can to keep it this way. One city, Kristadt, is a locus of activity for these drones, but its secretive government prevents further study. Remote observation confirmed the existence of numerous tunnels that lead into Eos' interior within the city.

Over sixty percent of the Phaethon's components are located around Gira Gira. The main component is a ring composed primarily of tungsten alloy that orbits within Gira Gira's atmosphere. Only a kilometer wide, the ring gathers all the energy needed. To transfer this energy, Phaethon uses a Faux Pylon. The ring on Eos spins as it absorbs thaumic energy. It is this spin that allows the entire structure to retain its shape. Phaethon often discharges excess energy in the form of electrical current. Large cities on Eos are consequently located near discharge points.

Major Cities


Flag	Name	Population	Type	Allegiance
File:Drusidia3.png	Scipio	497 Billion	Capital City	Greater Martial Consilium
	Civestadt	408 Billion	Capital District	Quintet Payotari Association
	Err	355 Billion	Duchy	Greater Martial Consilium
	Paradigm	217 Billion	City State	Nisrine Collective
	Civeehol	185 Billion	City State	Quintet Payotari Association
	Alphos	176 Billion	Palatinate	Greater Martial Consilium
	Haviir	128 Billion	City State	Quintet Payotari Association
	Lowa	104 Billion	Palatinate	Greater Martial Consilium
	Osametu	97 Billion	City State	Quintet Payotari Association
	Kristadt	86 Billion	Margraviate	Greater Martial Consilium
	Tonuur	80 Billion	City State	Quintet Payotari Association
	Aztaya	77 Billion	County	Greater Martial Consilium
	Tajuura	75 Billion	City State	Quintet Payotari Association
File:Altgraviate of Yakusoku.png	Yakusoku	54 Billion	Altgraviate	Greater Martial Consilium

Physical Geography

Major Seas

Eos has two trillion bodies of liquid, water or otherwise, on its surface that are larger than one hectare in area. Seas are defined as bodies of liquid with areas greater than half a percent of Eos' total surface. The "Dark Side of Eos" has its seas, but the largest ones generally mirror the below seas albeit with lower volumes.


Name	Surface Area	Percentage of Eos Occupied	Composition
Isochron Sea	2.83 Trillion km²	8.05%	Water
Sensen Sea	2.51 Trillion km²	7.14%	Water
Etoile Sea	2.40 Trillion km²	6.82%	Water
Platinum Sea	1.60 Trillion km²	4.55%	Water
Ka'a Sea	478 Billion km²	1.36%	Water
Boreal Sea	432 Billion km²	1.23%	Water
Framboise Sea	295 Billion km²	0.84%	Water
Superboreal Sea	239 Billion km²	0.68%	Brine
September Sea	228 Billion km²	0.65%	Lead