Úmbra is the sixth major celestial object around Lumenoferos. Despite being on a more distant orbit than Vel, Úmbra has a much hotter climate. This is due to its extremely dense atmosphere, which produces a greenhouse effect.
Between the high temperature, an atmospheric pressure that is comparable to that of the deepest underwater trenches of Etéra, and a mildly corrosive composition of the atmosphere, Úmbra is an extremely hostile environment that only specialised craft can explore, preferably without staying too long. While there are semi-regular research and prospecting expeditions to the planetary surface, so far most mining guilds tasked with large-scale extraction of any noteworthy deposits lean towards considering the process too expensive, difficult and risky to be worth it, even for highly exotic alchemicals.
The planet's name comes from a reference to shadow in a now-dead language, an allusion to an ancient tale that it's the furthest planet from the sun that is always shadowed from its light by one of its siblings.
Planetary Parameters[edit | edit source]
mean distance 2.2 au perihelion 2.0 au aphelion 2.4 au axial tilt 20° annual period 1183.5 Etéran days, 4734 local days. local day 6.0 hours
mass 3.51 (2.096e25 kg) diameter 1.6 (2e7 m) density 0.8 (4.4 g/cm³) surface gravity 1.3 (13 m/s²) escape velocity 16 km/s
vulcanism moderate tectonics light climate infernal
temperature average 269°C (542 K) periphelion 279°C (552 K) aphelion 261°C (534 K) illumination 0.16
hydrographics 5% (water) tidal range 0.09m atmosphere composition N2, CO2, H2O, and others pressure 98 MPa (98,300 kPa)