Litoria: the Planet
- 1 General
- 2 Name
- 3 Physical characteristics
- 4 Orbital characteristics
- 5 Formation
- 6 Surface
- 7 Chronology
- 8 Shape
- 9 Chemical composition
- 10 Internal structure
- 11 Evolution of life
- 12 Heat
- 13 Tectonic plates
- 14 Hydrosphere
- 15 Atmosphere
- 16 Weather and climate
- 17 Magnetic field
- 18 Planetary Motion
- 19 Moon
- 20 Habitability
- 21 Geography
- 22 Climate
- 23 Natural disasters
- 24 Biosphere
- Litoria is the middle planet of the three in its star system. The inner planet is a rocky terrestrial planet without an atmosphere. The outer planet is a gas giant.
- This is the only planet of the three having plate tectonics. At present the surface of the planet is composed of one giant continent which is larger than the one ocean. There are scattered islands in the ocean. The ocean is bordered by two high mountain chains. These separate the two habitable coasts from the interior desert. There is an ice cap on each pole which prevents travel by land from one coast to the other.
- The ocean and its coasts are the reference for direction so that, with the ocean as the center, the shore to the left is known as the Western Shore and that to the right as the Eastern Shore.
- It has one moon.
- Off-worlders have named the planet "Litoria" (< the Latin litus, litoris, shore) from the fact that there are only two shores on the planet.
- mean radius 5,778 km./3,590 mi. (Earth 6,371 km.; Venus 6,051.8 km.; Mercury 2,439.7 km.)
- mean circumference 36,286 km./22,500 mi.
- flattening .00248887
- surface area 11,228,581 km2/46,801,085 mi.2
- water 11,923,574 km2/7,407,000 (41%)
- land 17,158,315 km2/10,660,000mi.2 (59%)
- volume 456,674,562,012 km3/283,800,000,000mi3
- escape velocity 8.2 km./s.
- sidereal rotation period 0d 25h 0m 38.2s
- axial tilt 15.457°
- surface temperature
- minimum -85.4° C/ -121.7° F (Earth -128.6° C/ -199.5° F)
- mean 15.8° C/ 60.4° F (Earth 14° C/ 57.2° F)
- maximum - 60.2° C/ 140.4° F (Earth 57.8° C/ 136° F)
- surface pressure - 90.2 kPa
- atmosphere composition
- 76% nitrogen
- 21.5% oxygen (Earth 20.95%)
- 0.9% argon
- 0.1% carbon dioxide
- 1.5% water vapor
- aphelion 147,380,590 km./91,578,053 mi.
- perihelion 143,098,003 km./88,920 mi.
- semi-major axis 145,189,300 km./90,220,000 mi. (Earth 149,498,261 km.)
- eccentricity 0.0072
- orbital period 384.0002 days
- inclination 1.2° to Litoria's sun (7.155° to Sun's equator)
- The planet was formed 3.5 billion years ago, and life appeared on its surface within a billion years. Since then, Litoria's biosphere has significantly altered the atmosphere and other abiotic conditions on the planet, enabling the proliferation of aerobic microorganisms as well as the formation of an ozone layer which, together with Litoria's magnetic field, blocks harmful radiation, permitting life on land. The physical properties of Litoria, as well as its geological history and orbit, have allowed life to persist during this period. Litoria is expected to continue supporting life for another 1.5 billion years, after which the rising luminosity of its sun will eliminate the biosphere.
- Litoria's outer surface is divided into several rigid segments, or tectonic plates, that gradually migrate across the surface over periods of many millions of years. About 41% of the surface is covered with a salt-water ocean; the remainder consists of one supercontinent and an archipelago in the middle of the ocean, straddling the equator. There are ice caps at each of the poles. So, on a map of the continent, the ocean is shown bordered on each side by the habitable coasts and on top and bottom by the ice caps. Plate tectonics have pushed the four continental plates together so that very high mountain ranges have risen on each side of the continent. These ranges are far enough inland so that there is a coastal plain and a piedmont region on both coasts. The mountains are high enough so that a rain shadow is formed and the interior is a dry desert, with the occasional oasis. Litoria's interior remains active, with a thick layer of relatively solid mantle, a liquid outer core that generates a magnetic field, and a solid iron core.
- Litoria’s terrain varies greatly from place to place. About 41% of the surface is covered by water, with much of the continental shelf below sea level. The submerged surface has mountainous features, including a mid-ocean ridge system, as well as undersea volcanoes, oceanic trenches, submarine canyons, oceanic plateaus and abyssal plains. The remaining 59% not covered by water consists of two coastal plains and foothills, two pole-to-pole mountain chains, a large inland desert between the mountain chains and two icecaps, both of which are mainly over land.
- The elevation of the land surface of Litoria varies. The lowest point is in a valley in the interior desert which is 398 m. (1,306 ft.) below sea level. The highest point measured from sea level is the summit of a mountain in the western mountain chain which rises to an altitude of 7,839 m. (25,720 ft.) above sea level.
- The earliest dated solar system material is dated to 3.5529 ± 0.0006 billion years ago, and by 3.54 billion years ago Litoria and its two companion planets in the solar system formed out of the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the sun. This assembly of Litoria through accretion was largely completed within 10-20 million years. Initially molten, the outer layer of Litoria cooled to form a solid crust when water began accumulating in the atmosphere. The moon formed shortly thereafter, 22.96 billion years ago.
- Litoria’s natural satellite provides ocean tides, stabilizes the axial tilt and gradually slows the planet’s rotation. The moon was formed as a result of a large object with about 10% of Litoria’s mass impacting Litoria in a glancing blow. Some of this object’s mass would have merged with Litoria and a portion would have been ejected into space.
- Outgassing and volcanic activity produced the primordial atmosphere. Condensing water vapor, augmented by ice and liquid water delivered by asteroids and the larger proto-planets and comets produced the ocean. The newly-formed sun was only 70% of its present luminosity, but a combination of greenhouse gasses and higher levels of solar activity served to raise Litoria’s surface temperature, preventing the ocean from freezing over.
- There was a rapid growth of the continental crust followed by a long-term steady continental area. Over several hundreds of millions of years, the surface continually reshaped as continents formed and broke up. The continents migrated across the surface, occasionally combining to form a supercontinent. The present supercontinent recombined roughly 300-250 million years ago.
- The shape of Litoria is that of an oblate spheroid, a sphere squished along the orientation from pole to pole such that there is a bulge around the equator. This bulge results from the rotation of Litoria, and causes the diameter at the equator to be 68 km. longer than the pole to pole diameter. The average diamer of the reference spheroid is about 9,556.5 km.
- The mass of Litoria is approximagtely 5.98 x 1024 kg. It is composed mostly of iron (33.3%), oxygen (30.1%), silicon (14.2%), sulfur 2.6%), nickel (1.5%), calcium (1.3%), and aluminum (1.8%), with the remaining 1.1% consisting of trace amounts of other elements. Due to mass segregation, the core region is composed of iron (91.8%), with smaller amounts of nickel (4.8%), sulfur (3.3%), and 1% trace elements.
- The interior of Litoria is divided into layers by their chemical or physical properties. The outer layer of Litoria is a chemically distinct silicate solid crust, which is underlain by a highly viscous solid mantle. The crust is separated from the mantle by a thin layer. The thickness of the crust varies, averageing 6 km. under the ocean and 30-50 km. under the continent. The crust and the cold, rigid top of the upper mantle are collectively known as the lithosphere, and it is of the lithosphere that the tectonic plates are comprised. Beneath the lithosphere is the asthenosphere, a relatively low-viscosity layer on which the lithospere rides. Important changes in crystal structure within the mantle occur at 410 and 660 km. below the surface, spanning a transition zone that separates the upper and lower mantle. Beneath the mantle, an extremely low viscosity liquid outer core lies above a solid inner core. The inner core rotates at a slightly higher angular velocity than the remainder of the planet, advancing by 0.1-0.5° per year.
Evolution of life
- Highly energetic chemistry produced a self-replicating molecule about 3.3 billion years ago, and 0.5 billion years later the first common ancestor of all life existed. The development of photosynthesis allowed the sun’s energy to be harvested directly by life forms; the resultant oxygen accumulated in the atmosphere and formed in a layer of ozone in the upper atmosphere. The incorporation of smaller cells within larger ones resulted in the development of complex cells called eukaryotes. True multicellular organisms formed as cells within colonies and became increasingly specialized. Aided by the absorption of harmful ultraviolet radiation by the ozone layer, life colonized the surface of Litoria. Evolution has followed a path similar to that on the planet Earth up until the mass extinction recorded in the geology of the planet. The cause of the extinction is not yet known, but it occurred before the evolution of mammals and eliminated the large dinosaurs and reptiles. Life on Litoria today consists of all the familiar terrestrial life forms with the exception of mammals.
- Litoria’s internal heat comes from a combination of residual heat from planetary accretion (about 20%) and heat produced through radioactive decay (80%). The major heat-producing isotopes in Litoria are potassium-40, uranium-238, uranium-235, and thorium-232. At the center of the planet, the temperature may be up to 7,000° K. (6,727° C, 12,140° F) and pressure could reach 360 GPa. Because much of the heat is provided by radioactive decay, scientists believe that early in Litoria’s history, before isotopes with short half-lives had been depleted, Litoria’s heat production would have been much higher. The extra heat production, twice present-day at approximately 3 billion years ago, would have increased temperature gradients within Litoria, increasing the rates of mantle convection and plate tectonics, and allowing the production of igneous rocks such as komatiites that are not formed today.
- Total heat loss from Litoria is 5.1 x 1013 watts. A portion of the core’s thermal energy is transported toward the crust by mantle plumes, a form of convection consisting of upwellings of higher-temperature rock. These plumes can produce hotspots and flood basalts. More of the heat in Litoria is lost through plate tectonics, by mantle upwelling associated with mid-ocean ridges. The final major mode of heat loss is through conduction through the lithosphere, the majority of which occurs in the oceans because the crust there is much thinner than under the continents.
- The mechanically rigid outer layer of Litoria, the lithosphere, is broken into pieces called tectonic plates. These plates are rigid segments that move in relation to one another at one of three types of plate boundaries: convergent boundaries, at which two plates come together; divergent boundaries, at which two plates are pulled apart; and transform boundaries, in which two plates slide past one another laterally. Earthquakes, volcanic activity, mountain building, and oceanic trench formation can occur along these plate boundaries. The tectonic plates ride on top of the asthenosphere, the solid but less viscous part of the upper mantle that can flow and move along with the plates, and their motion is strongly coupled with patterns convection inside Litoria’s mantle.
- As the tectonic plates migrate across the planet, the ocean floor is subducted under the leading edges of the plates at convergent boundaries. At the same time, the upwelling of mantle material at divergent boundaries creates mid-ocean ridges. The combination of these processes continually recycles the oceanic crust back into the mantle. Because of this recycling, most of the ocean floor is less than 100 million years old.
- Litoria’s hydrosphere consists chiefly of the single ocean, but technically includes all water surfaces on the planet, including the polar ice caps, several lakes, many rivers, and underground waters down to a depth of 2,000 m. (6,562 ft.). The deepest underwater location is the mid-oceanic ridge with a depth of -6,285 m. (-20,620 ft). The average depth of the ocean is 2,700 m. (8,858 ft.). About 94% of the water is saline, while the remaining 6% is fresh water. Most of the fresh water, about 74.7%, is currently ice. Sea water has an important influence on the planet’s climate, with the ocean acting as a large heat reservoir.
- Litoria’s atmosphere has no definite boundary, slowly becoming thinner and fading into outer space. Three-quarters of the atmosphere’s mass is contained within the first 13 km. (8.1 mi.) of the planet’s surface. This lowest layer is called the troposphere. The height of the troposphere varies with latitude, ranging between 9 km. (5.6 mi.) at the poles to 18.5 km. (11.5 mi.) at the equator, with some variation due to weather and seasonal factors.
Weather and climate
- Energy from the sun heats the troposphere and the surface below, causing expansion of the air. This lower density air then rises, and is replaced by cooler, higher density air. The result is atmospheric circulation that drives the weather and climate through redistribution of heat energy.
- The primary atmospheric circulation bands consist of the tradewinds in the equatorial region below 30° latitude and the westerlies in the mid-latitudes between 30° and 60°. Ocean currents are also important factors in determining climate, particularly the thermohaline circulation that distributes heat energy from the equatorial oceans to the polar regions.
- Water vapor generated through surface evaporation is transported by circulatory patterns in the atmosphere. When atmospheric conditions permit an uplift of warm, humid air, this water condenses and settles to the surface as precipitation. Most of the water is then transported to lower elevations by river systems and usually returned to the oceans or deposited into lakes. Atmospheric circulation, topological features and temperature differences determine the average precipitation that falls in each region.
- Litoria can be subidvided into specific latitudinal belts of approximately homogeneous climate. Ranging from the equator to the polar regions, these are the tropical, subtropical, temperate, and polar climates.
- Litoria’s magnetic field is shaped roughly as a magnetic dipole, with the poles currently located proximate to the planet’s geographic poles. According to the dynamo theory, the field is generated within the molten outer core region where heat creates convection motions of conducting materials, generating electric currents. These in turn produce Litoria’s magnetic field. The convection movements in the core are chaotic, and periodically change alignment. This results in field reversals at irregular intervals averaging a few times every million years. The most recent reversal occurred approximately 740,000 years ago. The field forms the magnetosphere, which deflects particles in the solar wind.
- Viewed from the celestial north pole, the motion of Litoria, the moon and their axial rotations are all counterclockwise. Viewed from a vantage point above the north poles of both the sun and Litoria, Litoria appears to revolve in a counterclockwise direction about the sun.
- The Hill sphere, or gravitational sphere of influences (the maximum distance at which Litoria’s gravitational influence is stronger than that of the more distant Sun and planets) of Litoria is about 1,000,000 km in radius. Objects must orbit Litoria within this rotation, or they can become unbound by the gravitational perturbation of the sun.
- Apart from meteors within the atmosphere, the main apparent motion of celestial bodies in Litoria’s sky is to the west at a rate of 15°/h = 15'/min. This is equivalent to an apparent diameter of the Sun or Moon every two minutes; the apparent size of the Sun and the large Moon are approximately the same.
Axial tilt and seasons
- Because of the small axial tilt of Litoria, the amount of sunlight reaching any given point on the surface varies over the course of the year. This results in a slight seasonal change in climate, with summer in the northern hemisphere occuring when the north pole is pointing toward the sun, and winter taking place when the pole is pointed away. During the summer, the day lasts longer and the sun climbs higher in the sky. In winter, the climate becomes generally cooler and the days shorter. Above the Arctic Circle, an extreme case is reached where there is no daylight at all for part of the year, a polar night. In the southern hemisphere the situation is exactly reversed, with the south pole oriented opposite the direction of the north pole.
- By astronomical convention, the four seasons are determined by the solstices, the point in the orbit of maximum axial tilt toward or away from the sun, and the equinoxes, when the direction of the tilt and the direction to the Sun are perpendicular. However, these equinoxes and solstices are not known to the Litorians.
- The changing Litoria-sun distance results in an increase of about 0.01% in solar energy reaching Litoria at perihelion relative to aphelion. Since the southern hemisphere is tilted toward the Sun at about the same time that Litoria reaches the closest approach to the Sun, the southern hemisphere receives slightly more energy from the Sun than does the northern over the course of a year. However, this effect is much less significant than the total energy change due to the axial tilt, and most of the excess energy is absorbed by the higher proportion of water in the southern hemisphere.
- The most widely accepted theory of the moon's origin states that it was formed from the collision of a large body with the early Litoria. The moon is a large chunk that was captured by the planet’s gravitational pull.
- The moon orbits the planet on the same plane. Periodically the moon eclipses the sun.
- The gravitational attraction between Litoria and its moon causes the tides on Litoria. This same effect has led to its tidal locking, i.e., its rotation period is the same as the time it takes to orbit Litoria, As a result, it always presents the same face to the planet. As the moon orbits Litoria, different portions of its face are illuminated by the sun, leading to the lunar phases. Because of its tidal interaction, the moon recedes from Litoria at a rate of 20 mm. per year.
- mean radius - 1.911.3 km (0.4 "earths")
- flattening - .00128
- surface area - 129.396.23 km2
- volume - 29,231,759,981.8 km3
- sidereal rotation period - synchronous
- axial tilt - 5.125° (to orbital plane)
- orbital characteristics:
- semi-major axis - 681,828 km
- eccentricity - 0.009
- orbital period - 48.01 days
- inclination - 0.51° to the ecliptic
- A planet that can sustain life is termed habitable, even if life did not originate there. Litoria provides the requisite conditions of liquid water, an environment where complex organic molecules can assemble and sufficient energy to sustain metabolism. The distance of Litoria from the sun, as well as its orbital eccentricity, rate of rotation, axial tilt, geological history, sustaining atmosphere and protective magnetic field all contribute to the conditions necessary to originate and sustain life on this planet.
- The surface of the planet Litoria consists of one large continent (composed of four tectonic plates). This continent covers about 60% of the surface. The remaining 40% is covered by a salt-water ocean, with a few scattered volcanic islands, which stretches from pole to pole.
- Plate tectonics has pushed the four continental plates together so that very high mountain ranges have risen on each coast of the continent. These ranges are far enough inland so that there are a coastal plain and a piedmont region on both coasts. This habitable region extends from about two to four miles wide at the ice caps to several hundred at the equator.
- There are ice caps at each of the poles.
- There are the usual terrestrial biomes, from tundra in the north and south, through grasslands and woodlands, to rain forest along the equator.
- The seaward slopes of the mountain ranges are covered with various deciduous and coniferous forests.
- The mountains are high enough that a rain shadow is formed. As a result an arid desert covers the interior, with the occasional oasis (lewiyi tefe). In the northern summer meltwater from the northern ice cap produces a seasonal river. In the southern summer similarly a seasonal river is produced. The gradual slope of the land from the mountains to the center of the desert and the alternating flow of these two rivers result in a lake in the center of the desert whose average size does not diminish from evaporation in the desert heat. And because of the semiannual inflows of fresh water from the poles, the lake's salinity remains low. Unfortunately, the difficulty in crossing the mountains and the great distance across the desert to the lake make living around the lake impossible for the Litorians. It is, however, a major habitable region for wildlife.
- A number of rivers flow down the seaward slopes of the mountains to the ocean. Lakes and ponds dot the lowlands, the piedmont and the mountains.
- Climate is much as it is on planet Earth, with polar, moderate, continental and tropical zones. Given that the habitable biomes only exist in the small coastal regions between the ocean and the mountains, these zones are relatively small in area.
- The largest zone is the interior intramontane desert the covers almost half of the planet's surface.
- The typical terrestrial disasters occur: flooding, blizzards, hurricanes. The planet is relatively quiet, at present, tectonically, with only the occasional earthquake (etihu) in the desert.
- At present there is no volcanic activity on the continent, but there are active volcanos on some of the mid-ocean islands.
- Snow is common in the winter in the northern and southern latitudes and snow can be seen on the summits of the taller mountains on the islands.
- In a year of low precipitation there is the possibility of steppe wildfires ( ǵiǵo isu).
- When the spring temperature is unusually high, the quick thawing of snow and glacier may cause flooding in some of the watercourses.
- A planet’s life forms are sometimes said to form a "biosphere". The Litorian biosphere is generally believed to have begun evolving about 2.5 billion years ago.
- The biosphere is divided into a number of biomes, inhabited by broadly similar plants and animals.
- On land primarily latitude and height above sea level separate biomes.
- Biomes lying within the Arctic Circle, Antarctic Circle or in high altitides are relatively barren of plant and animal life, while the greatest latitudinal diversity of species is found at the equator.
- With respect to biomes, the two shores of Litoria are mirror images of each other.