Hierarchy overview for EARTH

Level = -4 WORLD
Level = -3 MATTER
Level = -2 BODY
Level = -1 PLANET
  1. EARTH
    1. EARTH_ATMOSPHERE
      1. CLOUD
      2. SNOW
      3. RAIN
    2. EARTH_SURFACE
      1. EARTH_PHYSICAL   -->
      2. EARTH_POLITICAL   -->
    3. EARTH_MANTEL
    4. EARTH_CORE
    5. ORGANISM
      1. PLANT   -->
      2. ANIMAL   -->