System Specs:
- Stellar Mass: 0.8 Sol Masses
- Stellar Class: K0
- Luminosity: 0.4 Sol
- Planets: 4
- Moons: 0
- Asteroid Belts: 1
- Asteroids: 1
- Objects: 0
Acheron is a poorly-explored inhospitable system consisting of four terrestrial worlds, one of which is tidally locked and another that is actually a double-planet body. Prospecting has identified several resources of note, though no organizations or business interests are rushing to lay claim to them.
The system was the site of a battle during the turians’ Unification War in their early history.
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Planets Directory:
- Farthorl
- Altahe
- asteroid belt
- Grosalgen
- Imaneya
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Farthorl:
- Orbital Distance: 0.3175 AU
- Orbital Period: 0.2 Earth-years
- Keplerian Ratio: 0.8
- Radius: 6,506 km
- Day Length: 0.2 Earth-hours
- Atmospheric Pressure: 0.69 atm
- Surface Temp: 239 °C
- Surface Gravity: 0.8 g
- Mass: 0.826 Earth-masses
A modest terrestrial planet, Farthorl has an atmosphere of carbon dioxide and chlorine. The crust is mainly composed of sulfur with deposits of nickel. The terrain is extremely rough – a patchwork of craggy, overlapping craters dating back to the formation of the solar system. Farthorl is tidally locked to the star Acheron. The day side has never been fully mapped.
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Altahe:
- Orbital Distance: 0.8 AU
- Orbital Period: 0.8 Earth-years
- Keplerian Ratio: 0.8
- Radius: 4,404 km
- Day Length: 53.8 Earth-hours
- Atmospheric Pressure: 0.98 atm
- Surface Temp: 36 °C
- Surface Gravity: 1.1 g
- Mass: 0.521 Earth-masses
- Satellites: special
Altahe is an exceptional form of planet called a Roche World. Put simply, it is one half of a pair of small and unusually dense terrestrial worlds (Altahe and Ontahe) that orbit each other so closely, they effectively share a single atmosphere. That does not mean one could fly from one to the other, but both have identical atmospheres and dust from one often can be found on the other.
Both worlds share an atmosphere of nitrogen and ethane. The surface is warm, and mainly composed of silica dust and dark basaltic rocks, with extensive deposits of heavy metals and radioactives. Tidal effects from Ontahe create constant heavy wind.
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Grosalgen:
- Orbital Distance: 11.13 AU
- Orbital Period: 41.5 Earth-years
- Keplerian Ratio: 0.801
- Radius: 5,198 km
- Day Length: 28.9 Earth-hours
- Atmospheric Pressure: 0.53 atm
- Surface Temp: −175 °C
- Surface Gravity: 0.6 g
- Mass: 0.396 Earth-masses
An enigmatic rock and ice planet, Grosalgen has a thin atmosphere of carbon dioxide and ethane. The surface is composed of frozen water and chlorine.
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Imaneya:
- Orbital Distance: 22.2 AU
- Orbital Period: 117.7 Earth-years
- Keplerian Ratio: 0.79
- Radius: 11,621 km
- Day Length: 56.4 Earth-hours
- Atmospheric Pressure: 0.88 atm
- Surface Temp: −185 °C
- Surface Gravity: 0.9 g
- Mass: 2.966 Earth-masses
Though exceptionally large for a terrestrial world, Imaneya is composed of water ice with a core of various carbonaceous compounds. It has a density only half that of Earth, and an atmosphere of nitrogen and carbon monoxide. The surface is composed of surprisingly pure water ice, with a high albedo.
Trivia
By “surprisingly pure water ice with a high albedo” we are to understand a composition like that of Enceladus, Bond albedo over 0.9 and geometric albedo over unity.
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