For a forge world, ::-viride has an atmosphere unusually suitable to human life. At least it has for the long phase of its excentric orbit that has is stray far from its parent star. At the height or viridian summer, though, the warming of the atmosphere has the mutagens and neurotoxins, the by-products of the colossal alechemic factory landscapes, otherwise stored in the uppermost layers of cloud rain down as a powdery crystalline substance. As long as the summer snowfall persists, ::-viride is effectively uninhabitable. Midsummer only lasts a few days, though, and afterwards the fallen snow is quickly re-sublimated and rises back up into the higher atmosphere. The rest of the viridian year lasts some 298.46 years Terran standard. By the careful calculations of the techpriests, this makes investment into protective measures inefficient. The ::-viride’s population of menials and workers is exchanged after each summer.
Four points for identifying how the name was derived.