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
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)