|1.0287 AU 161,969,614.61 km|
|360.02 days, or 1 Thegyan year|
Average orbital speed
|30.663 km/s (68,884 mph; 110,858 km/h)|
|Known satellites||2 natural satellites: Thegye A 5 A, 5 B|
|Composition by volume||78.08% nitrogen (N₂)
20.95% oxygen (O₂)0.97% other
Thegye, also known as the World, is the fifth planet from Thegye A and the only to harbor multi-cellular life. Thegye formed over 2 billion years ago. Thegye's gravity interacts with other objects in space, especially Thegye A and the two moons that orbit around it. Thegye orbits around the Sun in 360.02 solar days, a period known as an Thegye sidereal year. During this time, Thegye rotates about its axis 360.02 times, that is, a sidereal year has 360.02 sidereal days.
Thegye's axis of rotation is tilted with respect to its orbital plane, producing seasons on the planet. The gravitational interaction between Thegye and its moons causes tides and stabilizes Thegye's orientation on its axis.
Thegye's outer layer (lithosphere) is divided into several rigid tectonic plates that migrate across the surface over many millions of years. About 30% of Thegye's surface is land consisting of continents and islands. The remaining 70% is covered with water, mostly by oceans but also lakes, rivers and other fresh water, which all together constitute the hydrosphere. The majority of Thegye's polar regions are covered in ice. Thegye's interior remains active with a solid iron inner core, a liquid outer core that generates Theyge's magnetic field, and convecting mantle that drives plate tectonics.
Within the first 700 million years of Thegye's life, single-cellular life appeared in the frozen-over oceans and began to affect Thegye's atmosphere and surface, leading to the proliferation of anaerobic and later, aerobic organisms. In the history of life on Thegye, biodiversity has gone through periods of expansion, and punctuated by mass extinctions. Over 99% of all species that ever lived on Thegye are extinct. Over 30 million humans live on Thegye and depend on its biosphere and natural resources for their survival.
- 1 Chronology
- 2 Physical Characteristics
- 3 Orbit and Rotation
- 4 Habitability
- 5 Human geography
- 6 Moons
In theory, a solar nebula partitions a volume out of a molecular cloud by gravitational collapse, which begins to spin and flatten into a circumstellar disk, and then the planets grow out of that disk within Thegye A. A nebula contains gas, ice grains, and dust. Also according to theory, planetesimals formed by accretion, with the primordial Thegye taking 100 million years (Mys) to form.
During the formation of Thegye, a planet crashed into the surface, creating an asteroid belt orbiting around Thegye. Afterwards, this belt would begin to fall apart with the growth of two separate moons, in which is now present today in Thegye's sky. The belt is still visible today as it's now a functional part of Thegye as a ring system.
Thegye's atmosphere and oceans were formed by volcanic activity, and outgassing water vapor from these sources condensed into the oceans, augmented by water and ice from asteroids and comets. Atmospheric "greenhouse gases" kept the oceans from freezing when the relatively new Sun had only 80% of its current luminosity. 350 million years from when Thegye was formed, a magnetic field developed around the planet, which helped prevent the newly created atmosphere from being stripped away by the solar wind.
A crust formed when the molten outer layer of Thegye cooled to form a solid. Continents formed by plate tectonics, a process ultimately driven by the loss of heat from Theyge's interior. Over the periods of hundreds of millions of years up until the modern day, continents have assembled and broken apart.
Origin of life and evolution
Chemical reactions led to the first self-replicating molecules about 920 million years ago The evolution of photosynthesis allowed the Sun's energy to be harvested directly by life forms. The resultant molecular oxygen accumulated in the atmosphere and due to interaction with ultraviolet solar radiation, formed a protective ozone layer 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 became increasingly specialized. Aided by the absorption of harmful ultraviolet radiation by the ozone layer, life colonized Thegye's surface. Ever since life was introduced, there have been two mass extinctions. Mammalian life has diversified over the past 400 Mys, and several million years ago an ape-like animal such as Orrorin tugenensis gained the ability to stand upright. This facilitated tool use and encouraged communication that provided the nutrition and stimulation needed for a larger brain, which led to the evolution of humans. The development of agriculture, and then civilization, led to humans having an influence on Thegye and the nature and quantity of other life forms that continues to this day.
Thegye's expected long-term future is tied to that of the Sun. In around 7 billion years, the Sun's luminosity and temperature will start to increase due to hydrogen exhaustion. If Thegye is still habitable, Thegye's increasing surface temperature will accelerate the inorganic carbon cycle, reducing CO2 concentration to levels lethally low for plants (10 ppm for C4 photosynthesis). The lack of vegetation will result in the loss of oxygen in the atmosphere, making animal life impossible. Thegye is expected to be habitable until the end of photosynthesis about 7 billion years from now.
The Sun will evolve to become a red giant in about 7 billion years. The Sun at this timewill expand to 50 times its present size. Thegye's fate is less clear. As a red giant, the Sun will lose a considerable amount of its mass. Most, if not all, remaining life will be destroyed by the Sun's increased luminosity (peaking at about several times its present level).
The shape of Thegye is nearly spherical. There is a small flattening at the poles and bulging around the equator due to Thegye's rotation. To second order, Thegye is approximately an oblate spheroid.
Thegye's mass is approximately 1 Thegyan Mass. It is composed mostly of iron, oxygen, silicon, magnesium, sulfur, nickel, calcium, and aluminum, with the remaining consisting of trace amounts of other elements. Due to mass segregation, the core region is estimated to be primarily composed of iron, with smaller amounts of nickel, sulfur, and other trace elements.
The atmospheric pressure at Thegye's sea level averages 1 atm, with a scale height of about 8.5 km. A dry atmosphere is composed of 78.084% nitrogen, 20.946% oxygen, 0.934% argon, and trace amounts of carbon dioxide and other gaseous molecules.
Thegye's biosphere has significantly altered its atmosphere. Oxygenic photosynthesis evolved, forming the primarily nitrogen-oxygen atmosphere of today. This change enabled the proliferation of aerobic organisms and, indirectly, the formation of the ozone layer due to the subsequent conversion of atmosphere O₂ into O₃. The ozone layer blocks ultraviolet solar radiation, permitting life on land. Other atmospheric functions important to life include transporting water vapor, providing useful gases, causing small meteors to burn up before they strike the surface, and moderating temperature. This last phenomenon is known as the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the ground, thereby raising the average temperature. Water vapor, carbon dioxide, methane, nitrous oxide, and ozone are the primary Without this heat-retention effect, the average surface temperature would be significantly cooler, and life on Thegye probably would not exist in its current form.
Weather and Climate
Thegye'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 11 km (6.8 mi) of the surface. This lowest layer is called the troposphere. Energy from the Sun heats this layer, 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 thermal energy.
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 falls 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. This water cycle is a vital mechanism for supporting life on land and is a primary factor in the erosion of surface features over geological periods. Precipitation patterns vary widely, ranging from several meters of water per year to less than a millimeter. Atmospheric circulation, topographic features, and temperature differences determine the average precipitation that falls in each region.
The amount of solar energy reaching Thegye's surface decreases with increasing latitude. At higher latitudes, the sunlight reaches the surface at lower angles, and it must pass through thicker columns of the atmosphere. Thegye's surface can be subdivided into specific latitudinal belts of approximately homogenous climate, ranging from the equator to the polar region.
The gravity of Thegye is the acceleration that is imparted to objects due to the distribution of mass within the planet. Near Thegye's surface, gravitational acceleration is approximately 9.8 m/s². Local differences in topography, geology, and deeper tectonic structure cause local and broad, regional differences in Thegye's gravitational field, known as gravity anomalies.
The extent of Thegye's magnetic field in space defines the magnetosphere. Ions and electrons of the solar wind are deflected by the magnetosphere; solar wind pressure compresses the dayside of the magnetosphere, and extends the nightside magnetosphere into a long tail. Because the velocity of the solar wind is greater than the speed at which waves propagate through the solar wind, a supersonic bow shock precedes the dayside magnetosphere within the solar wind. Charged particles are contained within the magnetosphere; the plasmasphere is defined by low-energy particles that essentially follow magnetic field lines as Thegye rotates; the ring current is defined by medium-energy particles that drift relative to the geomagnetic field.
During magnetic storms and sub storms, charged particles can be deflected from the outer magnetosphere and especially the magnetotail, directed along field lines into Thegye's ionosphere, where atmospheric atoms can be excited and ionized, causing the aurora.
Orbit and Rotation
Thegye's rotation period relative to the Sun--its mean solar day--is 86,400 seconds of mean solar time.
Thegye orbits the Sun at an average distance of about 3.7 trillion km every 360.02 mean solar days, or one sidereal year. The orbital speed of Thegye averages an approximate 30.794 km/s, 68,884 mph, or 110,858 km/h.
Thegye, along with the Thegyan System, is situated in the Kentaurus Galaxy and orbits around 33,510 light-years from its center.
Axial Tilt and Seasons
The axial tilt of Thegye is approximately -21.8° with the axis of its orbit plane, always pointing towards the Celestial Poles. Due to Thegye's axial tilt, the amount of sunlight reaching any given point on the surface varies over the course of the year. This causes the southern hemisphere to experience summer while the northern hemisphere experiences winter in the months of June through early September. During the summer, the day lasts longer, and the Sun climbs higher in the sky. In winter, the climate becomes cooler and the days shorter. In northern temperate latitudes, the Sun rises north of true east during the summer solstice, and sets north of true west, reversing in the winter. The Sun rises south of true east in the summer for the southern temperate zone and sets south of true west.
Above a certain high latitude, an extreme case is reached where there is no daylight at all for part of the year, up to six months at the poles, a polar night. In the Southern Hemisphere, the situation is exactly reversed.
A planet that can sustain life is termed habitable, even if life did not originate there. Thegye provides liquid water--an environment where complex organic molecules can assemble and interact, and sufficient energy to sustain metabolism. The distance of Thegye from the Sun, as well as its orbital eccentricity, rate of rotation, axial tilt, geological history, sustaining atmosphere, and magnetic field all contribute to the current climatic conditions at the surface.
A planet's life forms inhabit ecosystems, whose total is sometimes said to form a "biosphere". Thegye's biosphere is though to have begun evolving about -- years ago. The biosphere is divided into a number of biomes, inhabited by broadly similar plants and animals. On land, biomes are separated primarily by differences in latitude, height above sea level and humidity.
Natural resources and land use
Thegye has resources that have been exploited by humans and those alike. Those termed non-renewable resources, such as fossil fuels, only renew over geological timescales.
Large deposits of fossil fuels are obtained from Thegye's crust, consisting of resources such as coal and natural gas. Mineral ore bodies have also been formed within the crust through a process of ore genesis, resulting from actions of magmatism, erosion, and plate tectonics. These bodies form concentrated sources for many metals and other useful elements.
Thegye's biosphere produces many useful biological products for humans, including food, wood, oxygen, and the recycling of many organic wastes. The land-based ecosystem depends upon topsoil and fresh water, and the oceanic ecosystem depends upon dissolved nutrients washed down from the land.
Natural and environmental hazards
Large areas of Thegye's surface are subject to extreme weather such as tropical cyclones, hurricanes, or typhoons that dominate life in those areas. Many places are subject to earthquakes, landslides, tsunamis, volcanic eruptions, tornadoes, sinkholes, blizzards, floods, droughts, wildfires, and other calamities and disasters.
Cartography, the study and practice of map-making, and geography, the study of the lands, features, inhabitants and phenomena on Thegye, have historically been the disciplines devoted to depicting Thegye. Surveying, the determination of locations and distances, and to a lesser extent navigation, the determination of position and direction, have developed alongside cartography and geography, providing and suitably quantifying the requisite information.
Orbiting around Thegye are a total of two moons orbiting around it, varying in size and distances, named Thegye A5A and Thegye A5B. These two moons all have differing characteristics from each other. Additionally, the gravity from these moons cause the natural tides to form. These tides are not too chaotic, nor too calm, but right in the medium.