Aethra

Aethra is a Industrial Sky-world, the fourth habitable moon of Thelyn, a 4th planet in the Europa solar system, which is located at the edge of Garon Nebulae, Segmentum Tempestus. Aethra is a mountainous industrial world, that supplies the Federation with vast amounts of both refined and unrefined ores and minerals. It was colonized under the initiative of the Europan Planetary Federation, after the secession from the Imperium of Man.

992.M40 to 354.M41
Aethra was colonized as the last world during the first expansion, mostly due to mineral riches hidden beneath the surface, and the still increasing demand for raw minerals of Europan industry, especially the rare earth elements, that are present in abundance on Aethra. Aethra was also an ideal candidate for the industry that produces large amounts of toxic waste as a byproduct, as most of the surface not habitable anyway.

355.M41-367.M41
At the end of the 355.M41, a catastrophe happened, killing millions of people within seconds. The mountain on which the capital city, Helios, was built on, exploded and collapsed, hurling rubble kilometers away. It was caused by a massive pressure build-up of volatile gasses inside and under the mountain, ale set alight by hot magma. The cataclysmic explosion was heard all over the planet and the shockwave caused further damage across the whole hemisphere. All people were considered lost as if somebody miraculously survived the explosion and the collapse, the toxic gases below the cloud level would mean certain death within hours. The city was rebuilt at a safer location and named New Helios. In the central square, a monument reminds the loss of 8 million souls.

378.M41-825.M41
During the deep mining operation in the Carnrane Ridge mine, a strange, yellow-ish ore was struck. Since this element was yet unknown, the mine was temporarily closed and the ore analyzed. Results showed it has remarkable electrical properties and reacts with high-energy photons in a very peculiar way. It is a room-temperature superconductor (an electrical conductor with no internal resistance) and when illuminated with intense sunlight, it becomes a voltage source. It quickly found its use throughout the federation. The ore was named Ferrum Solar and in refined form, it is usually called Solar Steel. Within several decades, many more deep mines were opened to satisfy the skyrocketing demand for this new element.

Landscape & Nature

 * The landscape is predominantly mountainous, with tall peaks and deep valleys in between, all covered in ice and snow. Planet has only a few oceans and rivers, but due to volcanic activity, lava fields and rivers of molten magma are very common. This is also the reason why the world is designated as Sky-world. The atmosphere is full of toxic volcanic gases, such as Sulphur, Methane, or Nitrogen, although the highest, and lethal concentration of those gases is only below the cloud level. The air above is safe to breathe.
 * Above the cloud level, plants are limited mostly to moss and small bushes, but under the cloud level, plants evolved to thrive from the naturally toxic environment and take shape of various creepy and alien-looking plants.
 * Fauna of this world is quite limited as well, with most species of both categories being small, with the only exception of Netherian Sky Rays, which is a huge, ray-like flying creature traveling in flocks and hunting for swarms of insects or smaller avian creatures.

Population, Society & Culture

 * With the toxic environment down below the clouds, people are forced to live above them, in cities and settlements built around the steep mountain peaks and atop the mountain ridges that are frequently blasted with strong, cold winds. Alternatively, some mining settlements are present below the cloud level. Those are required to be air-tight and anyone who has to venture out is required to wear a full-body protective suit, along with a breathing apparatus.
 * Due to the weather condition, 91% of the population lives in the mountain cities, 8% in the air-tight settlements and the remaining 1% living in the wilderness and remote locations, like weather stations or monitoring outposts.
 * Due to the fragmented population and difficult transportation limited only to air-travel or armored trains, every city is likely to be quite different from all other cities, culture-wise.
 * Prison labor is widely utilized in the mines, with the worst criminals sentenced to the most dangerous mines in exchange for a shorter sentence. The mortality rate is high, but the vision of having the sentence shortened to one-tenth of the original length makes it still attractive.

Notable locations

 * New Helios - A new Capital city build on a mountain plateau located in between tall mountains. It houses around 5 million people and serves as one of the major spaceports for the region.
 * Ruins of 'old' Helios - Now nothing but rubble and broken rocky formation below the cloud level, a sad reminder of what nature is capable of.
 * Mount Torringvor - Biggest, tallest and still active volcano on the entire planet. Its throat is clearly visible from space.
 * Carnrane Ridge deep mines - So far, this mine reaching over 2 kilometers below the 'sea level' and its shafts spanning over hundreds of square kilometers is far the biggest mine of Ferrum Solar yet discovered.
 * Niverheim deep mines - An already abandoned mine, yet the deepest. Its deepest shaft reaches little over 6 kilometers under the 'sea level'. The temperatures in the deepest areas were already incompatible with human life and mines had to use heat-resistant full-body suits.

Notable people

 * Nasreen Davar - Famous geologist and volcanologist. She successfully predicted several earthquakes, saving thousands of lives.
 * '227-336587N' - An inmate serving a life sentence in the deep mines. He's been there for over 60 years and doesn't even remember his name. Others call him just 'Hans'.

Armed Forces
Aethra is home to over 80 regiments of all sizes and types, yet some stand above the rest due to their qualities, equipment or training utilized the best on this particular world.
 * Aethran Airborne regiments - Majority of the Aethran regiments are, for obvious reasons, airmobile and are trained in such tactics. The specialty of these regiments is that instead of armored vehicles, they have squadrons of gunships, fighters, and bombers permanently attached to them.
 * Aethran Chem-corps - Units trained and equipped to operate in a polluted, toxic, corrosive or in any other hostile environment. Gasmasks and thermal-insulated, chemically-resistant full-body protective suits are standard-issue equipment.
 * Aethran Mountain Rangers - Light infantry units trained in cold weather and mountain warfare.
 * Aethran Defense regiments - Units dedicated to the defense of the individual cities. They are trained in urban warfare, guerilla tactics and, as one of the few Aethran regiments, posses armored vehicled and abundance of heavy weapons.