@pepper2000 according to P2K_CIV4FeatureInfos and CIV4FeatureInfos following features may exist on terrains:
Lunar Crater - Moon
Asteroids - Space and Deep Space (Cislunar space and unused terrain?).
Black Hole - Deep Space (Unused terrain?)
Oort Cloud - Transneptuntian and Transtellar
Sednoid - Transneptunian
Blue Dwarf, Blue Giant - Orion Arm and Milky Way
Brown Dwarf, Rogue Planet - Transtellar
Carbon/Chthonian/Desert/Hot Jupiter/Mini Neptune/Super Earth/Water planets, White Dwarf - Orion Arm and Transtellar
Dwarf Galaxy - Local Group and Virgo Supercluster
Galaxy - Local group, Virgo Cluster and Cosmos
Planetary Ring, Small Moon - Inner&Outer Solar System and Transneptunian
Quasar - Cosmos and Distant Cosmos
Supermassive Black Hole - Galactic Core, Local Group and Virgo Supercluster
It seems it is outdated and needs adjustments.