Natura - nature actualia - actual entities Mundus Plinius - physical world Astra Plinius - celestial bodies Universe (Supercluster) Virgo-Hydra-Centaurus Supercluster (Supercluster) Virgo Supercluster (Cluster) Local Group (Galaxy) Milky Way Galaxy veter. (Spiral arm) Orion Arm (Region) Local Bubble Local Interstellar Cloud (Planetary system) Solar System (Planet-satellite system) Earth System (Planet) Earth veter. "spheres" (Earth) (Sphere) Biosphere (Earth) - zone of life "terrestrial and freshwater ecoregions" (Bioregion) New World (Biogeographic realm) Nearctic "terrestrial ecoregions" (Nearctic) (Ecoregion complex) Sierra Madre Oriental and Occidental Pine-Oak Forests (Nearctic) (Terrestrial ecoregion) Sierra Madre Occidental pine-oak forests (Nearctic) "United States" (Sierra Madre Occidental pine-oak forests) "Arizona" (United States; Sierra Madre Occidental pine-oak forests) Kitt Peak National Observatory (United States: Arizona)