Although it is the nearest planet to the Pybus Sun, the tiny world of Pybus I is cold year round and naturally uninhabitable to most species. Its highly toxic atmosphere is composed of an unusual composition of gases generated from the planet's volcanic activity, and the settlements that have sprung up across its surface in the wake of various mineral resource discoveries over the years are shielded to provide recycled breathable air to its inhabitants.

Due to the planet's seismic instability, structures must be carefully engineered to withstand the frequent tremors, and they are designed with elasticity in mind. The seismicity is a constant challenge for the burgeoning mining industry, but the mineral deposits are valuable enough that they have successfully driven a thriving local economy.

Little of the planet's surface remains unsettled and much of the local wildlife has been hunted to extinction, requiring frequent import shipments from the neighboring planets within the system in order to sustain the population with regular food supplies. Some of the southern glaciers on Pybus I proved too precarious to support construction work, and they remain among the few sparse regions on the planet where native wildlife species can still be found. However, local scientists studying the planet's ecology suspect that the native ecosystem has already been damaged irreparably.