View source for Ametrasa system

{{Icons|Start|Aidus}}
{{Infobox planetary system
| title = Ametrasa system
| image = Ametrasa system diagram with names.svg
| image_size = 300px
| image_alt = Ametrasa system with sizes, but not distances, to scale
| caption = {{longitem|Ametrasa and its planets<br />''(distances not to scale)''|style=padding:2px 0 4px 0;}}
| age = 6.34 billion years
| location = {{longitem| {{w|Orion Arm}}, {{w|Milky Way}}}}
| system_mass = 1.0042 Ametrasa masses
| neareststar = {{longitem|{{W|Gliese 676|Moreya}} (3.38&nbsp;ly)}}
| nearestplanetary = {{longitem|Moreya system (3.38&nbsp;ly}}
| semimajoraxis = {{longitem|5.24 AU}}
| Kuiper_cliff = ≈10 AU
| noknown_stars = yes
| stars = 1{{nbsp}}(Ametrasa)
| planets = {{longitem|{{hlist|4:{{nbsp}}[[Amenukashi]]|[[Heizan]]|[[Ryuga]]|[[Yomei]]}}}}
| outerplanetname = [[Yomei]]
| dwarfplanets = {{longitem|{{hlist|2:{{nbsp}}Kama|Tsukai}}}}
| satellites = 17
| minorplanets = {{longitem|≈750 thousand}}
| comets = 872 <small>(confirmed)</small>
| roundsat = 
| roundsatlink =
| inclination = ≈86°{{nbsp}}(ecliptic)
| galacticcenter = ≈27,100&nbsp;ly
| orbitalspeed = 211.8&nbsp;km/s
| orbitalperiod = 240.791 Myr
| spectral = {{W|G-type star|G3IV}}
| frostline = ≈5 AU
| heliopause = ≈25 AU
| hillsphere = ≈1 ly
}}
The '''Ametrasa system''' consists of the {{w|planetary system}} orbiting the {{w|main sequence}} {{w|G-type star}} '''[[Ametrasa (Star)|Ametrasa]]'''. Four planets directly orbit Ametrasa, some of which possess numerous {{W|natural satellites}}; in order from innermost to outermost, the planets are [[Amenukashi]], [[Heizan]], [[Ryuga]], and [[Yomei]]. Amenukashi is a {{W|chthonian planet}}, while the outer three are {{W|gas giant}}s; [[Osukune]], a satellite of the gas giant Ryuga, is the only celestial body known to harbor {{W|life}}.

The star Ametrasa is approximately 6.34 billion years old, with a surface temperature of 5820 {{W|Kelvin}}. It sits on the cusp of {{w|subgiant}} classification, although it is believed to be a particularly large and bright main sequence {{W|dwarf star}}. Amenukashi orbits very closely to Ametrasa, while Heizan and Ryuga interact through a 2:1 {{w|orbital resonance}}. Amenukashi also orbits Ametrasa the fastest, with an {{w|orbital period}} of only 9.63 days, whereas Yomei, the farthest planet, orbits Ametrasa every 11 and a half years. Osukune, a natural satellite of Ryuga, sits in the {{W|habitable zone}} of Ametrasa and uniquely possesses a {{w|biosphere}}. The system has a large amount of unstably orbiting {{W|planetesimal}}s and {{W|space debris}} due to centuries of unfettered exploitation during the [[First Skeletarchy]].

Humans arrived in the Ametrasa system roughly 3800 years before the present, settling on Okusune's most temperate continent, [[Kento]]. Variable conditions in the {{w|ultraviolet}} emissions of Ametrasa made the early days of human colonization difficult, paired with the generally high levels of {{W|volcanism}} and violent weather patterns on the ocean-moon. The [[Skeleton Rebellion]] of the 13th century Aj. saw a fundamental shift of rulership towards the {{W|robot}}ic [[Skeleton (Kento)|skeleton]]s, whose domination over humanity would remain undisturbed for seven centuries during the [[First Skeletarchy]]. Departing through the transformation of Ryuga's outermost moon into the form of a massive spacecraft, the First Skeletarchy left what little remained of human civilization in near-total disarray. After two centuries of constant bombardment from orbitally decaying space debris, humanity saw a brief period of resurgence, only to once again fall to the mysterious [[Grid Failure]] of the 27th century. The [[Second Skeletarchy]] emerged as a result, and for a time ruled peacefully, but the internecine [[Skeleton War]] pushed all of civilization once more to the brink of extinction.

In the centuries since the Skeleton War, humanity has remained bound to the ocean-moon Okusune, particularly the continent Kento, which is the only known harbor of biological life in the observed stellar neighborhood. Although humanity was once a space-faring species, such feats are now far beyond the level of technological sophistication possessed by any extant population of sentient beings. {{w|Genetic engineering}} has resulted in the emergence of the [[Ariman|arimen]] and [[Sunoman|sunomen]] subspecies of human, which cohabit with these baseline humans on Kento. As of the 39th century Aj., the estimated population of all living sentients in the Ametrasa system is a mere 16.88 thousand.

==Exology==
==History==
==Society==
==See also==
*[[Sol system (Sanctuary Stars)|Sol system]]
*{{W|Gliese 676|Moreya system}}

[[Category:Ametrasa]]
[[Category:Ara (constellation)]]
[[Category:Planetary systems with four confirmed planets]]