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) Atmosphere (Earth) - layer of air (Phenomenon) Meteors (Phenomenon) Hydrometeors (Phenomenon) Clouds Phenomenon Low Clouds Genus Stratus L. Howard, 1803 1 Stratus nebulosus 2 Stratus fractus 3 Stratus opacus 4 Stratus translucidus 5 Stratus undulatus