Orbital characteristics
Perigee 831,390 km (.00557 AU)
Apogee 872,930 km km (.00583 AU)
Semi-major axis 852,160 km (.00569 AU)
Eccentricity .0243
Orbital period 48.883 Earth Days
Average orbital speed 75073 km/hm, 20.853km/s
Inclination 3.9831° to Polysiton's Equator
Physical characteristics
Mean radius 4450.8 km
Equatorial radius 4,452.1 km
Polar radius 4,449.5 km
Flattening .00065013
Circumference 27972.74 km
Surface area 2
Volume 3.6942x1011 km3 (about .34 Earths)
Mass 1.389x1024 kg (about .23 Earths)
Mean density 3.76 g/cm3
Equatorial surface gravity 4.674 m/s2 (Equatorial), 4.679 m/s2 (Polar)
Escape velocity 6.451 km/s (Equatorial) 6.453 km/s (Polar)
Sidereal rotation period 5.265 Polysitonian Days (7.91d, 189.84h)
Equatorial rotation velocity 147km/h
Axial tilt 1.05°
Surface temperature min mean max
Kelvin 218 293 339
Celsius −54.8 °C 20.8°C 65.9°C
Surface pressure 80.218 kPa (MSL)
Composition 47% Nitrogen, 32% Oxygen, 5% Methane 5% Xenon, 4% Carbon Dioxide, 4% Water vapor, 3% Other
Native Flora Arestes, Selenoxylon, Deikon
Native Fauna Lagikoanthropoi, Lagikoi

Seleukeia (Sphere Greek Σελευκεια, -ας) is one of Polysiton's natural satellites, alongside Euxeine. As a satellite to Polysiton, it is in a relatively fine position to host life, and given its mass, it has enough gravity to have its own atmosphere, allowing it to host life, although life is far harsher than it is in Polysiton.

Geography and GeologyEdit

Like Polysiton, Seleukeia features bodies of water. Unlike Polysiton, Seleukeia's surface is predominantly land, and bodies of water, although large, are largely local and surrounded by land rather than it defining landmasses. As such, concept of continents do not exist in Seleukeia, and the lagikoanthropoi define Seleukeia's regions nearly purely politically. The largest body of water in Seleukeia is Pontos Protogenetes, which alongside Thalassa Zoes and Lagikopontos consist the 3 major bodies of water in Seleukeia. Although Seleukeia has far smaller surface water, Seleukeia makes up for it somewhat with large bands of aquifer around its crust, meaning agriculture outside the river valley is not completely impossible.

Ecogeographically, the primary terrain of Seleukeia is dry forests consisting of Selenoxylon, meaning arable land is much more rare than it is in Polysiton. Sociogeographically, the most fertile lands are occupied by Lagikoanthropoi, Lagikoi often living at the outskirts of Lagikoanthropoi settlements.

Geologically, Seleukeia consists mostly of silica, with combination of other compounds to make it somewhat similar to Terra. Given its similarity to earth chemically, loess deposition occurs frequently in Seleukeia's many rivers, which compose a somewhat significant portion of Seleukeia's surface water. Seleukeia is also well endowed with mineral wealth, having a significant deposit of the metallic elements. Selenexylon makes it easier to tap into the elements, as Selenexylon crystallizes the minerals taken in excess and thus allow for easy harvesting for processing.