=^= 0.3.4 - Planetary Classification
Created by Captain Lirha Saalm on 01 Sep 2012 @ 12:48pm
Planetary Classification List
Introduction to Planets
In the Milky Way Galaxy there are 325 billion stars, not all of these have planets or anything for substantial than clouds of dust. At current counts however there are 432 billion planets, 175 billion are habitable. All planets can be graded between the classes below. Planets usually orbit a centre of high gravity, either a star or even two or another large body. It isn't unheard of for systems to even have two sets of binary stars orbiting each other. While planets can occur at varying distances from the stars those best suited to life occur in the temperate zone, warmed by the stars fusion but not too much. In lucky cases life can evolve, however less than 500,000 different planets have evolved their own life. Most easily habitable planets in the Federation are colonised, several less naturally suited words are terraformed to a more suitable class.
Class A - Geothermal
Class A planets are small, normally less than 10,000 km in diameter and extremely geologically unstable. Because of this they tend to be quite young planets, normally only in their first billion years of existence. Due to volcanic activity they have high amounts of carbon dioxide in their atmosphere that keeps them extremely hot. When this activity stops the planets tend to become Class C planets. Even protected surface missions are not advised, there is no natural life of any sort.
Class B - Geomorteus
Class B planets are small, normally less than 10,000 km in diameter and highly unsuited for humanoid life. They are normally quite close to the systems core with thin atmospheres of helium and sodium. Due to this make-up and the close distance to the sun or suns, they have mostly molten surfaces. During daylight, because of the thin atmosphere it can reach over five hundred degrees Kelvin, at night it can get as low as 73 Kelvin. With these extremes, life has never been known to evolve on these planets, however they have been known to occasionally have bacterial life on their surface from comet impacts.
Class C - Geoinactive
Almost all Class C planets start their lives as Class A planets and change once they stop being geologically active. Losing the atmosphere they had, they become completely barren, just a rock in space. Being more stable than Class A, they can be colonized with pressure domes and mined for resources. They are still normally less than 10,000 km in diameter and have limited gravity.
Class D - Dwarf
In some cases barely even planets, as small as a hundred kilometres in diameter up to four thousand they are made up of mostly of ice. Most planetary moons fall into this category as do most larger asteroids in a systems Kuiper Belt. Most do not support any sort of life and generally have minimal mineral resources but can be colonised via pressure domes.
Class E - Geoplastic
Class E planets are the first stage of the development of a habitable planet. From core to crust they are molten but cooling. They can have a range of atmosphere but tend to have high levels of carbon dioxides, hydrogen and helium. Being larger than a Class B at between 1Mn and 1.5Mn they are more able to retain their atmosphere, while still having very high temperatures and being hazardous to almost all forms of life. If the planet starts to cool to the extend they develop a crust they become a Class F planet.
Class F - Geometallic
Class F are planets at the most basic start of life. As volcanic activity starts to cool down and the crust solidifies, if a fluid medium such as water can form, life can as well. While still active and hostile to most humanoid life due to high levels of carbon dioxide and unstable surface temperatures, for a few minutes the air can be breathable. This class will normally only form in a system's temperate zone, else they remain Class E for the rest of their existence. As the planet cools further and becomes volcanically stable, they transition to Class G.
Class G - Geocrystalline
Class G planets are habitable. While volcanic activity is still sporadic, the cooler and older planet is able to sustain complex life. Algae and mosses start to form, along with soft animal life such as jellyfish. Oxygen is in abundance along with nitrogen and, while there wouldn't be food for them, humanoids can survive on these worlds indefinitely. They are rocky with developing oceans and seas but are silent worlds. Depending on state and position of the planet, a Class G can become a Class H, K, L, M, N, O or P world.
Class H - Desert
A Class H planet is almost entirely desert, at most they have only 20% of their surface covered in water. Young planets of four to six billion years old tend to be rocky while those that are older tend to be covered in sand. Life can evolve here but it is limited, plants tend to be small as do animals. Weather tends to be dry, sandstorms and still days with few clouds, some have snow on their poles and can experience wider variations of weather. They are often incapable of naturally supporting populations above a hundred million humanoid lifeforms.
Class I - Ice Giant (Uranian)
Class I planets are completely different from smaller molten core planets, their cores are mostly made of rock and ice. Layers of water, methane and ammonia make up the rest of the planetary body. They are large planets between 35Mn and 100Mn and tend to only form of the fringe of a solar system. They also tend to have very strong magnetic fields at each rotational pole.
Class J - Gas Giant (Jovian)
If Class I are large planets, Class J are giants. At between 50Mm and 500Mm the largest of them are on the verge of becoming dwarf stars. Made up of liquid and gaseous hydrogen, their cores even made up of hydrogen compounds. Winds of over 600 kph lick the surface during storms making them extremely hazardous. Due to their size and gravitational pull, they often can form rings of matter that fall into their orbit. Forming in the medium to outer areas of a solar system, they tend to be closer to the star than a Class I planet.
Class K - Adaptable
Class K planets are much like their Class H counterparts but the atmosphere is too weak. Only capable of supporting single cell life they aren't very habitable and fluctuations in temperature would kill most humanoids over a few days. They can, however, be colonised with pressurised domes.
Class L - Marginal
Class L worlds are young planets that haven't yet developed animal life. They tend to be covered in forests and plants that are broken down by simple organisms and fungi. Water is not common and those with less than 20% surface coverage fall to being Class H. These planets, however, are perfect for colonization and terraforming. Impact of native life is minimal and minimum effort is needed.
Class M - Terrestrial
Class M planets are perfect for most humanoid life, they are stable and can often evolve humanoid life and other complex animal life. The land masses are mostly rocky but covered in soil and vegetation, twenty to eighty percent of the planet is covered in water. The only other requirement is that is must have a breathable oxygen-nitrogen atmosphere and a temperate climate. Most species in the known universe originated from planets of this class. They are found in the ecosphere of a star that allows their development.
Class N - Reducing
Class N planets are failures when compared to Class M. While they appear in a similar location in a star's ecosphere, they are barely hospitable for any race. They are barren with temperatures that reach over 700 Kelvin. Massive amounts of carbon dioxide cover the surface and build up a pressure a hundred times that of an M Class world. This means that from space, it seems like the planet is entirely covered in clouds.
Class O - Pelagic
Class O planets are covered in water, to qualify a planet needs to be more than 80% surface water. Due to the water they absorb and store, a lot of the heat still reaches the planet, making the atmosphere very charged. They can support vast aquatic ecosystems as well as tropical islands on peaks above the water. These planets tend to have the most living matter of any other and teem with vast variations of species. While most do not evolve humanoid life, some do though they are normally aquatic.
Class P - Glaciated
Class P planets are almost exactly the same as Class O, only due to the atmosphere or star it orbits, it is cold. Average temperature never reaches above zero degrees centigrade so the entire planet it covered in ice. In this state the ice reflects heat rather than absorbs it, life finds it much harder to survive here. With preparation humanoids can survive on these worlds but there is very little to eat and without protection most would die in minutes.
Class Q - Variable
Class Q planets are rare occurrences that, due to unstable orbits or stars, constantly change what their surface conditions are like. Due to its orbit, it can both freeze and boil, be suitable for life and be hostile. Some are less pronounced and dapple between different ecospheres, deserts of a few miles next to tiny rainforests and swamps. This eclectic mix is more often caused by multiple stars in a system unlike the more wide spread extremes due to the planets orbit. Because of these extremes, life rarely evolves due to the instabilities, and colonisation is problematic.
Class R - Rogue
Class R planets are thrown from their home system by some event and then drift through space without a star. They often lose their atmosphere and life dies out, even if they don't lose their atmosphere they normally freeze unless the planet is able to produce its own heat from its core. These planets are rare and almost never colonised as their position is rarely stable.
Class S - Gas Supergiant
Vast planets in a range of colours, bigger by magnitudes than Class J they have all the matter to become stars but by fluke have failed. Their liquid metal core is under such pressure that it can give out its own light that can sometimes flare out of the hydrogen and helium surface.
Class U - Gas Ultragiant
If a Class S planet gains matter by consuming other planets or dust in a star system, it can keep growing to a Class U. These planets are the size of small stars and are right on the edge of critical mass. Once they reach it, the planet collapses in on itself, becoming a young star.
Class Y - Demon
Class Y planets come in a range of sizes, and while they have atmospheres, they are completely hostile to almost all known life. Radioactive, toxic air scours the surface at huge speeds. Temperature moves between huge highs and lows, and almost constantly covered in harsh storms, it would be better to be exposed to space than the surface of a Class Y.
Class Z - Zion
Similar in almost every way to a Class M world, Class Z worlds are impossibly rare, only two have been known to exist and only one still exists. Perfect for normal humanoid life with the absolute right balance of radiation, light, atmospheric gasses, low heavy metals and the right bacteria, the average life form can easily live twice as long on its surface as a Class M. The climate is balanced and hostile weather is very unusual, temperature over most of the planet is between 15-30 degrees centigrade. It is generally accepted that these planets are created rather than develop naturally, however exactly how is currently beyond current knowledge.
(Created by Kiri Cho, USS Galileo)
Categories: Science Database