Biosphere is the name given to the habitable area of an asteroid settlement. It consists of a cylindrical space hollowed out of the rock, which is then sealed and has a breathable atmosphere introduced. Usually the biosphere is planted, either as a park or as arable land, but occassionally, as in the case of the asteroid Sonora, the biosphere is flooded and turned into a giant freshwater lake.
This page is still very incomplete. If you have read Night’s Dawn recently and know something else about the subject of this page, then you can help by editing it!