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) Electrometeors Phenomenon Ignis - lightning 1 Phenomenon upper-atmospheric lightning 2 Phenomenon positive lightning 1970s 3 Phenomenon cloud-cloud lightning 4 Phenomenon dry lightning 5 Phenomenon rocket lightning 6 Phenomenon cloud-to-ground lightning 7 Phenomenon ground-to-cloud lightning 8 Phenomenon ball lightning