Eithlinn is a habitable moon in Via Aylathiya. The moon is the homeworld of the Dotsk and is capital and most populated natural body in Dotskgard. It orbits an artificial shell world known as Mili, despite originally orbiting a gas giant named Tuirne. Eithlinn itself has a population of 145 trillion, making it the most populated moon in Via Aylathiya. Due to the lack of a parent star, the main source of heat for Eithlinn is artificial heat beamed from Mili.
Accompanying Eithlinn are over forty other spherical natural bodies, many of which were moved from outside of Eithlinn's original system to orbit Mili. The largest of which is Anamnesis, the first world the Dotsk terraformed.
Most of the Eithlinn's original volcanic activity and natural surface has been altered by the Dotsk to suit their needs better, leaving little in the way of natural geography left. The moon has five layers made mostly of material brought in from asteroids orbiting Tuirne. These layers are covered in large numbers of buildings and other infrastructure in edition to large open spaces and parks for the sake of aesthetics. On the poles of the moon are massive radiators that emit large amounts of infrared light, cooling the ecumenopolis. Were it not for these radiators, the moon would very quickly heat to the point of killing its inhabitants.
Each concentric shell from the center becomes larger in area and mass. The mass of the moon has increased almost ten percent since the Dotsk first became Kardashev I. These layers are all artificially lit including the upmost layer, which itself is being enveloped in a sixth layer as of present day. All of these layers have large seas and are air-tight. As one gets higher in one of these layers, the amount of gas decreases until hitting the next layer, where it is almost a vacuum. Holes in the layers filled in constantly by a swarm of quadrillions of machines inspecting every square centimeter of the layers for damage. A large hole in the layers (something on the order of several dozen meters in scale) would leak large amounts of air into the lower layer. To combat these dangerous, and rare, occurrences, there are large machines placed roughly every one hundred meters capable of melting itself into a slurry of semi-liquid material able to quickly plug the hole until repair crews can arrive.
Across the moon are truly large towers, often twenty kilometers long and a kilometer and a half wide which link the layers. They support people, matter, and power throughout the moon. Many of them extend deep into the core, extracting all the power they can from it. They also server to radiate excess heat from the moon.
Most native species were relocated to stations orbiting Tuirne and onto the companion moon known as Erroi to make more room for Dotsk on Eithlinn. This life is mostly based on carbon with a large amount of arsenic and oxygen present. The lack of phosphorus in the area made it far too uncommon for life to incorporate it into their biologies, so life evolved with arsenic as the backbone of its genetic material instead. This caused phosphorous to become a valuable commodity to the ancient Dotsk, a material rivaling gold in value.
The large volumes of Hydrogen Sulfide present in the atmosphere, in addition to the large amount of carbon dioxide, methane, and sulfur dioxide, is vital to life on this moon. Eithlinn is over two light years away from its nearest star, making photosynthesis impossible. Instead, the lowest level of the food-chain relies heavily on chemosynthesis. Hydrogen Sulfide and Carbon Dioxide can be oxidized to produce sugars, releasing large amounts of pure sulfur. Most organisms which chemosynthesize end up becoming purple or yellow due to this release of elemental sulfur.
A large portion of the moon's biosphere relied on another exotic form of energy production, radiosynthesis. In the ocean, where life on the moon originated, the first meter of water absorbs almost all radiation hitting the moon. On land, however, the moon is often bombarded with high-energy waves. Every so often, particularly strong bouts of stellar radiation will hit Eithlinn. This first sterilized the land; however, life soon began to use this radiation to its advantage. The first "plants" emerging onto the land would mostly chemosynthesize like everything else. Additionally, these plants were able to evolve to radiosynthesizers when the moon becomes saturated with cosmic rays for up to a week at a time. Radiosynthesis is akin to photosynthesis, except it uses higher energy light than photosyntehsis does, allowing for elemental oxygen to begin building up in the atmosphere.
When Eithlinn first became a part of the wider economy of Via Aylathiya, its economy had no specific focus. The Dotsk developed a system similar to distributism, a system of economics in which the ownership of companies are spread widely among many individuals. A typical company would be owned by those that worked for it; however, the government was not allowed to interfere in the economy unless it is to maintain the distributist system. This economic system was strange, neither fully socialist or liberal like much of the rest of the galaxy.
At first, the government of Eithlinn was incredibly hostile to corporations. This foreign concept was immediately looked upon with disdain. Most believed it to be some form of authoritarianism or feudalism. After the collapse of its neighbor the Yohjan Confederacy in 0 CE, the planet found itself able to access the large number of resources it was cut off from previously. The government, fearing monopolies, banned corporations and forced them to return to the distrubitist form the nation had known previously. With this, the economy was able to expand rapidly.