Zelene Solar-system – Austin Bunton Designs

System Specs:

Stellar Mass: 0.78 Sol Masses
Stellar Class: K
Luminosity: N/A Sol
Planets: 4
Moons: 0
Asteroid Belts: 0
Asteroids: 0
Objects: 0

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Planets Directory:

Nepyma
Helyme
Epho
Gaelon

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Nepyma:

Orbital Distance: 0.8 AU
Orbital Period: 0.8 Earth-years
Keplerian Ratio: 0.8
Radius: 4,456 km
Day Length: 40.4 Earth-hours
Atmospheric Pressure: 0.55 atm
Surface Temp: 32 °C
Surface Gravity: 0.57 g
Mass: 0.276 Earth-masses

Tidally locked to the star Zelene, Nepyma has the expected “hot pole” and “cold pole.” Along the terminator is a thin band of nearly-habitable terrain. Unfortunately, the local biosphere is based on a chlorinated oxygen atmosphere. It is not sophisticated, but it has proven highly dangerous.

The asari surveyor Verallas landed on Nepyma in 1684 to study the local ecology. Unbeknownst to the crew, a handful of native chlorine-fixing microbes passed through biohazard screening and entered the ship. The Verallas returned to the port of Nos Parnalo on Illium, where the Nepyman microbes escaped into a temperate environment with plentiful unused chorine [sic].

The microbes devoured the chlorides in the earth; as metabolic byproducts, they produced toxic polychlorinated biphenyls (PCBs). By the time the infestation was contained, an area of nearly 30 square kilometers had been effectively turned into a toxic waste dump. Nos Parnalo had to be abandoned, accelerating the development of Nos Astra.

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Helyme:

Orbital Distance: 1.2 AU
Orbital Period: 1.5 Earth-years
Keplerian Ratio: 0.768
Radius: 5,522 km
Day Length: 44.4 Earth-hours
Atmospheric Pressure: 0.84 atm
Surface Temp: −15 °C
Surface Gravity: 0.87 g
Mass: 0.647 Earth-masses

Helyme is a “post-garden” world that once enjoyed an Earth-like oxygen-nitrogen atmosphere. It is still blessed with plentiful water, but a generally cold climate (and extreme seasonal shifts, courtesy of a 38-degree axial tilt).

Helyme is thought to be the homeworld of the arthenn, a spacefaring species which disappeared approximately 300,000 years ago. Precisely what happened to Helyme is still under debate. It appears a global extinction occurred, wiping out all native animal life forms more complex than zooplankton. Plant forms were not affected, but the lack of oxygen-breathing life caused oxygenation of the atmosphere. Plant life was reduced after lightning storms ignited global wildfires.

The leading theory for Helyme’s devastation is an out-of-control biological weapon. For this reason, landing is strictly prohibited. The corporations of Illium have emplaced a network of quarantine satellites to dissuade would-be looters from landing in the crumbling cities.

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Epho:

Orbital Distance: 1.56 AU
Orbital Period: 2.22 Earth-years
Keplerian Ratio: 0.77
Radius: 8,031 km
Day Length: 70 Earth-hours
Atmospheric Pressure: 0.98 atm
Surface Temp: −41 °C (12 at the equator)
Surface Gravity: 1.0 g
Mass: 1.574 Earth-masses

Epho is a rocky world with an atmosphere of oxygen and carbon dioxide. There are large craters scattered across its surface, obviously from hypervelocity kinetic impactors. Stretching between these locations are the shattered remains of magnetic levitation rail lines, which strongly suggests the craters represent the former locations of arthenni mining outposts or other settlements. The equatorial region contains an extensive network of canyons, formed by the planet’s abundant liquid water.

TRAVEL ADVISORY: Epho’s atmosphere is approximately 41% carbon dioxide at sea level. This level is 4 to 6 times that necessary to render most species unconscious within a few minutes of breathing it. Breathing masks must be worn at all times when on the surface of Epho.

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Gaelon:

Orbital Distance: 2.96 AU
Orbital Period: 5.7 Earth-years
Keplerian Ratio: 0.798
Radius: 63,539 km
Day Length: 8.9 Earth-hours
Atmospheric Pressure: N/A atm
Surface Temp: N/A °C
Surface Gravity: N/A g
Mass: N/A Earth-masses

Gaelon is surrounded by an extensive ring system. The inner rings are composed pulverized nano-manufactured carbon materials, thought to be the remains of an arthenni helium-3 mining infrastructure. The few pieces of larger debris found indicate a materials technology at least equal to the current galactic state-of-the-art.

The outer rings consist of water-ice, silicate dust, and the odd bit of rock. Analysis of the debris often show [sic] shock damage and evidence of rapid heating. Some para-historical theorists insist that the outer rings represent debris from a moon or moons destroyed by mass accelerator bombardment. This has been rejected by every reputable xenoarcheologist; while it is theoretically possible to destroy a small moon utterly with dreadnought bombardment, no species sees a compelling reason to do so.