View source for Siora

{{infobox planet
| name = Siora
| symbol_fn = Symbol_Siora.png
| image_fn = Oracia_Render_A1.png
| image_desc = Artistic rendering of the planet.
| pronunciation = {{IPA|s|i|ɔər|ʌ}}
| adjective = Sioran
| epoch = {{date|1|1|1556}}
| orbital_period = {{ul|392 days|{{small|1 year}}}}
| satellites = [[Luna|one natural satellite]]; <br/> n operational {{Other wiki|artificial_satellites|artificial satellites}}; <br/> 21,000 pieces of debris over 10 cm in size (as of {{Date|10|10|1562}})
| mean_radius = {{val|6,841.12|u=km}}
| equatorial_radius = {{val|6,852.58|u=km}}
| polar_radius = {{val|6,829.66|u=km}}
| flattening = {{val|0.0033561}}
| circumference = {{ul|{{val|43,056.03|u=km}} {{small|({{Other wiki|Equator|equatorial}})}}|{{val|42,912.01|u=km}} {{small|({{Other wiki|Meridional|meridional}})}}}}
| surface_area = {{val|588,117,672|u=km3}}
| volume = {{val|1.34113|e=12|u=km3}}
| mass = {{val|7.02840|e=24|u=kg}}
| density = {{val|5.24|u=g/cm3}}
| surface_gravity = {{val|10.02|u=m/s2}}
| temperature = {{ul|'''mean'''|{{val|285.15|u=K}}|{{val|12.00|u=degC}}|{{val|53.60|u=degF}}}}
| surface_pressure = {{val|112.6|u=kPa}} (at {{Other wiki|sea_level|MSL}})
| composition = {{ul|77.272% {{Other wiki|nitrogen}}|21.638% {{Other wiki|oxygen}}|01.045% {{Other wiki|argon}}|00.042% {{Other wiki|Carbon_dioxide|carbon dioxide}}|~1% {{Other wiki|water_vapor|water vapor}}|c=none}}
}}
Siora, often called '''the world''' in common usage, or '''Midlost''' (especially in {{Other wiki|fantasy_fiction|fantasy fiction}}), is the third {{Other wiki|planet}} from [[Sol]], the densest planet in the [[Sol System]], and one of two astronomical objects known to accommodate life. Siora's biodiversity has evolved over several hundred million years, expanding continually except when interrupted by {{Other wiki|extinction_event|mass extinctions}}. Although it's estimated that over 99% of all {{Other wiki|species}} are extinct, Siora is currently home to 10-15 million species, including several billion humans.

According to evidence from radiometric dating and other sources, Siora was formed around [[Age_of_Siora|four billion years]] ago. Within its first billion years, life appeared in its oceans and began to affect its [[Atmosphere of Siora|atmosphere]] and surface, promoting the proliferation of {{Other wiki|aerobic_organism|aerobic}} as well as {{Other wiki|anaerobic_organisms|anaerobic organisms}} and causing the formation of the atmosphere's {{Other wiki|ozone layer}}. This layer and the {{Other wiki|geomagnetic_field|geomagnetic field}} block the most life-threatening parts of the {{Other wiki|sunlight|sun's radiation}}, so life was able to flourish on land as well as in water. Since then, the combination of Siora's distance from the Sun, its {{Other wiki|Geophysics|physical properties}}, and its geological history have allowed life to persist.

Siora's {{Other wiki|lithosphere}} is divided into several rigid {{Other wiki|tectonic_plates|tectonic plates}} that migrate across the surface over periods of many millions of years. Siora's interior remains active, with a solid iron {{Other wiki|inner_core|inner core}}, a liquid {{Other wiki|outer_core|outer core}} that generates the magnetic field, and a thick layer of relatively solid {{Other wiki|mantle}}.

Siora {{Other wiki|gravitational_interaction|gravitationally interacts}} with other objects in space, especially the sun and [[Luna]]. During one orbit around the Sun, Siora rotates about its own axis 392 times, creating 392 [[solar days]], or one [[sidereal year]]. Luna is Siora's only natural satellite and began orbiting the planet about 3.5 billion years ago. Its gravitational interaction with Siora stimulates ocean {{Other wiki|tides}}, stabilizes the axial tilt, and gradually slows the planet's rotation.

== Etymology ==
The modern Lanlian ''Siöra'' {{OOC|''Siora'' is the OOC English spelling}} developed from Middle Lanlian ''Siore'', the term for: the ground, soil, dry land, and the globe. Siore was a [[Siore_(goddess)|personified goddess]] in [[Lanlanian paganism]]. While Siore was considered the embodiment of the world as a whole, [[Midlost_(goddess)|Midlost]] was the personification of the "human world".
[[Category:Siora]]
[[Category:Sol planets]]
[[Category:Terrestrial planets]]
[[Category:Habitable zone planets]]