Ötfaks T'halak

This planet is part of Stellar Civilizations.

Ötfaks T'halak /'øtfəks 'thalək/, commonly known as just T'halak, is the most populous planet of the Ha-Jin empire, located in the Miri star system. It is the home planet of the Uyck race, the most advanced race in the empire and the founder race of Ha-Jin. The planet also hosts the imperial capital, which is the Khamyong'a district, home to both the planetary and the imperial administration, the main universities and academies, as well as the headquarters of many government institutions and organizations.

T'halak is the coldest known planet to be a homeworld for intelligent life. The average surface temperature is -28°C (-18°F), which only rises above zero (32°F) in the equatorial, subequatorial and rarely in the tropical areas. As much as 74% of the surface is covered by glaciers 5 m (16 ft) to 8 000 m (26 000 ft) deep. The planet's flora is poorly developed and mostly made up of mosses and lichens, with forests found only in the equatorial regions, mostly coniferous, with the only exception of the Birkarím District Nature Reserve, home to the planet's only mixed forests. The natural fauna is almost entirely either extinct or critically endangered: thus, many species of wild land animals were exterminated either in the ancient times or later during the formation of the Uyck civilization. However, the projects of the restoration of the fauna do exist and are supported by the green parties.

Physical characteristics

T'halak is the fourth planet from its star, with the average distance (semi-major axis) of 252 940 080 km (157 169 679 mi), on the edge of the habitable zone. The planet's mass is 5.638×10²⁴ kg (94.4% of the mass of the Earth), which together with the radius of 6 256 km (98.2% of Earth's radius) provides the planet with a surface gravity of 9.61 m/s² (0.978 g), which in turn lets the inhabitants freely move on the surface and avoid reaching enormous size.

The planet has two natural satellites. The larger one, Ma'el, has a radius as large as 23% of that of T'halak and spins on an average distance of 380 000 km (236 000 mi). It is seen from the surface of the planet with a naked eye; it is home to military bases, training grounds, numerous laboratories and the only interstellar spaceport in the system. The smaller one, Nuss, is a mere 260 km (162 mi) wide, which is not enough for a moon to become spherical.

Mean solar (Mirian) day on Ötfaks T'halak is 29 hours and 8 minutes long, while the average sidereal day lasts for 29 hours 5 minutes 11.6 seconds. Consequently, a year, which is 755.9 Earth days long, is divided into 623.4 days, and the planet sees 624.4 rotations around its axis during this period of time.

The planet’s axis of rotation is tilted by 21 degrees relative to the orbital plane, which creates seasonal variations of surface temperature, some regions even have pronounced seasons, while above the 69th parallel polar days and polar nights happen. Polar latitudes are also famous for Polar Lights, resulting from the interaction of the charged particles (star wind) with the planet’s magnetic field.

Atmosphere

The atmosphere of T'halak consists of five main layers: troposphere, stratosphere, mesosphere, thermosphere and exosphere. Even though the exosphere and most of the thermosphere lay above the Kármán line, they are still considered part of the atmosphere in the scientific researches.

Troposphere

The troposphere is the lowest layer of the atmosphere, which makes up about 80% of the atmosphere's total mass. In the polar regions it is about 5-6 kilometers (3-4 mi) thick, whilst near the equator it’s thickness reaches its maximum at 10-12 kilometers (6-7 mi). The normal atmospheric pressure on the surface is 98 kPa (0.98 bar), with the temperature decreasing by 6.0°C every kilometer of altitude gain (17.4°F every mile).

The air in troposphere contains 76% nitrogen, 23% oxygen, as well as carbon dioxide, argon, methane and other trace gases. The high concentration of oxygen allows animals inhabiting the planet to freely consume it while breathing. At the polar latitudes the deposition of carbon dioxide can occur, forming solid CO₂, also known as dry ice.

Stratosphere

The stratosphere begins at an altitude of 8-15 km (5-9 mi) above the surface right after a thin interlayer known as tropopause, where the temperature does not change with height. The air in the entirety of the layer is unbreathable.

Up to 25 km (15 mi) an insignificant change in the air temperature can be recorded, and then up to 40 km (24 mi) the temperature begins to rise until it reaches -5°C (23°F). Above this altitude till 55 km (34 mi) the pressure continues to fall, while the temperature remains constant. This area is known as stratopause and is the border between stratosphere and mesosphere. Ozone layer lies within the stratosphere.

Mesosphere

Mesosphere ("the interlayer") is the next layer of the atmosphere after stratosphere, which begins at 55 km (34 mi) and ends at 90 km (55 mi). Temperature decrease of 3°C per km can be recorded here, which is why the lowest temperatures in the atmosphere are found in mesopause, the top layer of mesosphere (the historical minimum is 82 K / -191°C / -312 °F).

Thermosphere

The thermosphere is the fourth and the last layer of the atmosphere within the Kármán line (even though less than 0.01% of the thermosphere lays beneath the line, it still crosses this layer and technically it is the last one). The thermosphere is where the stellar wind and the magnetic field interact and thus the auroras occur.

The Kármán line is the altitude above the sea level where achieving lift is only possible at reaching the orbital speed, which no longer requires any lift. For Ötfaks T'halak this altitude equals 95 km (59 mi) and it is the exact altitude which is considered the higher boundary of the atmosphere. Turbopause, the border between to homosphere (the large part of the atmosphere where the mixtures of gases are homogenous enough and are not dissolved into components by gravity) and heterosphere (where the gases are distributed by gravity), also lays within thermosphere. The border is at an altitude of 110 km (68 mi).

The top edge of the thermosphere is at 800 km (500 mi) and is called thermopause. The air is so thin that the star's radiation is barely absorbed and the temperature remains constant. It is also considered a higher limit of the atmosphere.

Exosphere

The exosphere is the last layer of the atmosphere which extends from 900 km (560 mi) to 2500-3000 km (1500-1800 mi). The pressure here is so low that gas particles freely escape into space. Rare gas molecules collide with the stellar wind and since the speed of the particles is incredibly high (counting for hundreds of kilometers a second), this is the hottest layer of the atmosphere, where the temperatures can reach 1000°C (1832 °F) or more.

Beyond this altitude, the atmosphere is so thin that it is indistinguishable from the vacuum.

History

Pre-Uyck period

The Miri star system formed roughly 6 billion years ago from the gravitational collapse of a molecular cloud in the Milky Way galaxy. Since the matter was asymmetrically distributed inside the cloud, initially two different stars formed - Miri A and Miri B, whilst the latter had a mass approximately eight times smaller than that of the former and was a red dwarf. They orbited each other on a distance of a mere 3 million kilometers, which is only twice as much as the diameter of Miri A. As a result of gravitational interaction, after 10-15 million years after their formation the two stars merged into one.

Ötfaks T'halak appeared 20-30 million years after the formation of the system and was entirely covered by lava. The most common theory says that the planet formed because of collisions of different solid objects (initially particles of dust and rocks, later comets, asteroids and possibly dwarf planets) on the stellar orbit. Over time, as lava started gradually solidifying, the planet's atmosphere started to form, which was almost entirely composed of nitrogen with insignificant amounts of methane and argon.

70 million years after the formation, T'halak collided with a large comet Al-Uthmány, which blasted about 1.4% of the planet's mass to the orbit. It is this impact that brought most of the planet's water, at the time as vapor due to a sharp rise in the surface temperature. The blasted matter partially returned to the planet, but most of it formed the planet's two satellites - Ma'el, which is seen from T'halak with a naked eye, and Nuss, which is considered to be an asteroid.

After other 160 million years the bombings from space stopped, and the steam in the atmosphere started gradually condensing into clouds and then precipitating. Water began appearing on the planet, predominantly on the poles, as the surface was still too hot to handle water in its liquid state, though the surface was rapidly cooling down.

First Life Era (Karibalsa Age)

5.4 billion years ago, when most of the surface was covered in water, the first unicellular organisms appeared at the bottom of the ocean. The exact reason of appearance of life is unknown, but the two main and most prevailing theories - Natural Origin Theory, which suggests the natural formation of RNA spiral and cellar membrane out of more simple materials, and the Artificial Origin Theory, which suggests that the life was brought from the outside, eventually developing into more complex organisms. Plants, inhabiting different bodies of water released great amounts of oxygen into the atmosphere, which makes up 23% of its modern volume.

Formation of the civilization

Şonaký

Şonaký or Shonaky (literally - "preceders, ancestors", singular - Shonak, Şonak) is a common term for all animal species of T'halak that are ancestors of modern Uycks, up to Şonak Y'aiŕe (Wild Shonaky), which itself is an ancestor species of both modern Uycks and Þalab B'Öden (Thalabs of Öden), genetically the closest other animal species on Ötfaks T'halak.

Climate

T'halak is one of the coldest inhabited planets and the coldest one to be a homeworld for intelligent life. Although there are different types of climate on the planet, dividing the planet into climate belts is quite problematic, because apart from latitude, there are several other factors just as important (e.g. altitude above the sea level, the amount of precipitation, the distance from the ocean, etc.)

That is the exact reason why the climate is classified by the climate zones rather than climate belts in their classical definition.

Polar zone

The Polar Zone, also formerly known as Inaccessibility Zone till the end of the Machine Age, is the largest zone on the planet, which occupies most of the planet's ice cover.

The boundaries of the zone are vague and thus are a subject of debates. Some climatologists put the border at the 45th parallel since the entirety of the surface at this latitude is covered with ice (the extreme points of the oceans lay near both 44°N and 44°S). It melts only during the rare days when the temperature rises above water's freezing point (0°C or 32°F).

Others put the border at the so-called Aus Line, an imaginary curve line located between the 45th and the 50th parallels. Beyond this line, the oceans and ice-free land never get close enough to naturally support food chains. This understanding of Polar Zone is officially registered by the Ha-Jin Academy of Sciences.

Some scientists also add the equivalent of the Aus Line for the mountain glaciers, however behind this border very small areas lie (individually, they never exceed several hundred square kilometers) and they are considered a high-altitude climate zone rather than a par of the polar zone instead.

It is the coldest climate zone on T'halak, entirely covered by ice. Depending on the border, the maximum average temperature varies from -26°C (-15°F) to -33°C (-27°F). The Est mountains near the North Pole have the planet's lowest recorded average temperature of -107°C (-160°F). The absolute minimum (-148°C / -234°F), however, was registered at the Jal (Yaal) research station near the South Pole.

The territory of the polar zone lacks any natural flora or fauna, with the only inhabitants of the region being the bacteria, transported here by the snow storms, and the staff members of numerous factories, laboratories and other facilities found in the area. No historical settlements can be found here.

The 45th parallel is the border of both North and South Polar Research Districts, which are ones of the 27 first-level administrative divisions of T'halak. Although the territories of both districts do have population (e.g. the staff of the technical enterprises), they are considered uninhabited and thus governed directly by the planetary andministration.

Transition zone

Transition zone is a mostly barren climate zone on the planet, located between the Aus line and the Glacier Line. It is the smallest climate zone by area, as well as the most sparsely populated one.

Inside the Transition Zone, the ice does not melt entirely during an average year, which is the defining criteria for its outer border, the Glacier Line. This place does have some species of wild animals and several historical settlements, most of which appeared after the Industrial Revolution for the purpose of mining.

In the settlement of TBD, the temperature of -87°C was recorded, which is the lowest recorded temperature in any permanent settlement on the planet. This temperature is significantly lower than the sublimation point of carbon dioxide, one of the main components of the planet's atmosphere.

Tundra zone

Tundra is defined as the region between the Glacier Line and the Permafrost Line, therefore it is the area where snow does not cover the ground for the entirety of the year, but the soil has a thick layer of permafrost. This region covers roughly 70% of the planet's ice-free land and is by far the largest inhabited climate zone on T'halak.