Ratera is the third planet from Ixo and the only known place in the universe where life has originated and found habitability. Ratera is the only planet and one of two objects in the known Ixo System to possess liquid water on its surface. A majority of water on Ratera is in the ocean, with a majority of the remaining water being held in the polar regions as ice.
Ratera has a dynamic atmosphere that keeps temperatures relatively stable across the globe and protects the surface from most meteoroids and UV-light at entry. It has a composition of primarily nitrogen and oxygen. Water vapor is commonly found throughout the atmosphere and condenses to form vast clouds. Water vapor along with other greenhouse gasses, particularly carbon dioxide, creates the conditions that allow both liquid surface water and water vapor to exist via capturing the energy from Ixo's light. This process keeps the average temperate of the planet at around 12.8 °C.
Natural History[]
See Geological Timescale.
Formation[]
In theory, Ratera and the other planets formed around Ixo around 4.58 to 4.52 billion years ago. Ratera would've formed from a circumstellar disc made of dust, gas, and ice. If true, then a planetesimal would've formed via accretion, this primordial Ratera would've formed in the span of 50 to 100 million years.
Ratera's moon, Auter, is thought to be around 4.5 billion years old or younger. The leading hypothesis is that Auter formed from an accretion disc around Ratera after a theoretical Painia-sized object collided with the planet. It would've collided in a way where most of the mass would've merged with Ratera's whilst the rest would've been ejected and formed a disc around the planet. Between 4.2 and 3.8 billion years ago, numerous asteroid impacts caused significant change to the surface of Auter, and by interference, that of Ratera's.
After formation[]
Ratera's atmosphere and oceans were formed by volcanic activity and outgassing. Water vapor from these sources would've condensed to form oceans, augmented by water and ice from asteroids, comets, and other celestial bodies. The amount of water on Ratera since its origin is heavily debated, but it is entirely possible that the amount of water to fill the oceans has been on the planet since its formation. Other gasses from volcanic activity and outgassing would've created an atmosphere that would've prevented these oceans from freezing. It is estimated that around 3.6 billion years ago Ratera's magnetic field formed.
As the outer layers of Ratera cooled, crust began to form. It is estimated that the first continental crust formed between 4.4 to 4.3 billion years ago. Over the course of millions of years, new continental crust would be continued to be made via plate tectonics, and over time, these continental plates would merge to form the first super continent. Around 800 million years ago, this super continent began to split apart. The continents then later recombined around 560-550 million years ago to form Obenia, and then finally Fratuna around 270 million years ago which broke up around 190-170 million years ago.
The most recent pattern of ice ages began around 40 million years ago, and then intensified during the Pleistocene around 3 million years ago. Since then, much high and middle latitude places have undergone repeated cycles of glaciation and thawing every 20,000, 40,000, and 100,000 years. The last glacial period ended around 11,700 years ago.
Origin of life and evolution[]
Chemical reactions led to the first self-replicating molecules around four billion years ago. An estimated half a billion years later, the last common ancestor of all life on Ratera (LUCA) arose. The evolution of photosynthesis greatly changed life on Ratera, with lifeforms now being able to harvest energy from Ixo. As a result, molecular oxygen (O2) accumulated in the atmosphere and due to interactions with UV solar radiation, formed the ozone layer (O3) in the upper atmosphere. The incorporation of smaller cells into larger ones led to the evolution of eukaryotes. Shortly thereafter, multicellular colonizes became extremely specialized and further colonized Ratera. The earliest known fossil evidence of life is microbial mat fossils found in 3.5-billion-year-old sandstone in Galand, and biogenic graphite found in 3.82-billion-year-old metasedimentary rocks in Svalark, as well as possible evidence of life found in zircon crystals dated to at least 4 billion years.
During the Neoproterozoic, 1000 to 538.8 million years ago, much of Ratera had been covered in ice. This hypothesis has been termed "Snowball Ratera", and possibly happened multiple times. Following the Rimunian Explosion, 535 Mya, there have been at least five major mass extinctions and many minor ones. Apart from the proposed current Holocene extinction event, the most recent was around 66 Mya, when an asteroid impacted Ratera. Due to this extinction, Mammalian life diversified greatly since the last 66 million years, and several million years ago, an ape species in Ontura began to stand upright. This allowed for the use of tools and a larger developed brain, which eventually led to the evolution of elves. The development of agriculture, and civilizations, led to elves having an influence on Ratera and the nature and quantity of other life forms that continues to this day.
Orbit and rotation[]
One Rateran year is equivalent to around 88.9 Earthen days, and one Rateran day is equivalent to 25 Earthen hours.
Rotation[]
Ratera's rotational period relative to Ixo - its mean ixoar day - is around 90,000 seconds, 1,500 minutes, 25 hours, or 1.04 days. However, due to tidal deceleration, each day can vary by 0 to 2 milliseconds longer than the mean ixoar day.
Orbit[]
Ratera orbits Ixo, making Ratera the third closest planet to Ixo and part of the inner Ixo System. Ratera's average orbital distance from Ixo is around 58,343,000 kilometers (36,253,000 mi), or roughly 0.4 astronomical units (AUs). This distance means it takes roughly 3.24 minutes or 194.6 seconds for light from Ixo to travel to Ratera.
Ratera orbits Ixo every 88.9 mean ixoar days, or 0.243 years. The orbital speed of Ratera averages around 47.6 km/s, which is fast enough to travel across the diameter of Ratera in 4.37 minutes or to travel from Ratera to Auter in 65.58 minutes. Auter and Ratera orbit around a common barycenter every 9.68 days.
Axial tilt and seasons[]
The axial tilt of Ratera is roughly 13.4° with the axis of its orbit plane, always pointing towards the Celestial Poles. Due to the axial tilt of Ratera, the amount of light reaching any given point on the planet varies over the course of a Rateran year. This causes seasonal changes throughout the year with summer in the Northern Hemisphere occurring when the northern polar axis points towards Ixo, and in the Southern Hemisphere occurring when the southern polar axis points towards Ixo. During the summer, days last longer and Ixo climbs higher into the sky. In winter, the climate becomes colder and the days shorter. Above the Arctik Circle and below the Lemcan Circle there is no daylight at all for parts of the year, causing a polar night. These same latitudes also experience a midnight Ixo, where Ixo is visible throughout the whole day.
Geophysical characteristics[]
Geopolitical map of Ratera (2020)
Ratera has a rounded shape with an average diameter of around 12,482 km.
Due to the planet being geologically active, the planet has various topographic features, including local features such as the Zamfa Peninsula (8,325 km above sea level) and the Iwara Trench (-10,921 km below sea level).
Internal structure[]
Ratera's interior is similar to those of other terrestrial planets, behind divided into several layers by their chemical or physical properties. The outermost layer is a chemically distinct silicate solid crust which lays on top of a highly viscous liquid mantle. The thickness of the crust can vary greatly, with oceanic crust being significantly thinner than continental crust by a few dozen kilometers. The crust and colder upper part of the mantle are divided into several distinct tectonic plates.
Beneath these tectonic plates is the lower mantle, which is a liquid of low viscosity. Beneath the mantle is Ratera's core, which is divided into two sections, the outer core, which is liquid, and the inner core, which is solid.
Chemical composition[]
Ratera is primarily made up of various silicates and metals, as well as gasses. It is comprised mainly of iron (33.1%), oxygen (29.5%), silicon (18.2%), magnesium (11.2%), sulfur (1.4%), nickel (1.4%), calcium (1.3%), and aluminum (1.1%), with the remaining 2.8% consisting of trace amounts of other elements. Due to gravitational separation, the core is made primarily of heavier elements such as iron (93.1%), nickel (3.7%) and sulfur (2.4%), with the remaining 0.8% being trace amounts of other elements. A majority of the rocks that constitute the crust are oxides. An estimated over 98% of the crust of Ratera is made up of oxides of twelve elements, primarily oxides containing silicon (silicates), aluminum, iron, calcium, magnesium, sodium, or potassium.
Tectonic plates[]
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Ratera's tectonic plates: Marian Plates in brown, Tanisean plates in green, Heran plates is purple, Onturan plates in Pink, Maltisian plates in orange, Lemcan plates in blue, Poran plates in greenish blue, Gamtis Plate in red, and other minor plates in various colors.
Ratera's upper most layer, the crust, is made up of several tectonic plates. These plates are rigid segments that move relative to each other at one of three boundary types; at convergent boundaries, two plates come together; at divergent boundaries, two plates are pulled apart; and at transform boundaries, two plates slide past one another laterally. Along these plate boundaries, rateraquakes, volcanic activity, mountain-building, and oceanic-trench formation can occur.
As the tectonic plates migrate, oceanic crust is subducted under the leading edges of the plates at the convergent boundaries. At the same time, the upwelling of materials from the mantle at divergent boundaries creates mid-ocean ridges. These processes allow the recycling of the oceanic crust back into mantle. Due to this, most of the oceanic floor is less than 100 million years old. The oldest oceanic crust is found in the western Gamtis Ocean, which is estimated to be around 250 million years old. By comparison, the oldest known continental crust is around 4 billion years olds, although zircon crystals have been found dating to at least 4.3 billion years old.
The nine major plates are the Gamtis, Maria, Tanisean, Galand, Lemca, North Heran, South Heran, North Onturan, and South Onturan plates. Other semi-major plates include the Cocroenian, Marshallia, Creubia, Poran, Athia, Cialimaci, Svalark, and Guacanian plates to name a few. However, there a several other minor plates that are considered to be slightly independently active or are independently active of other major and semi-major plates.
Rater-Auter system[]
Auter is a large celestial body that orbits Ratera as its only known natural satellite. The origin of Auter is relatively unknown, however, it has been theorized and relatively accepted that a hypothetical celestial body of substantial size collided with an early Ratera, causing a ring of debris to be ejected into orbit around the planet. This ring, over time, condensed and formed Auter.