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) Hydrosphere (Earth) - layer of water (Drainage basin) Atlantic Ocean Basin (Drainage basin) American Mediterranean Sea Basin (America) (Drainage basin) Gulf of Mexico Basin (Drainage basin) Mississippi River Basin (United States, Canada) (Drainage basin) Arkansas River Basin (North America) (Drainage basin) Canadian River Basin (United States: Oklahoma, Texas, New Mexico) (Stream) Beaver River (United States: Oklahoma: Woodward County)