- Earth is the third planet from the sun
- Only planet known to have life on it
- 4.5 billion years old
- 71% water, with 97% of it in oceans
- It’s ever-changing
- Earth is a complex system of dynamically interacting subsystems and components
- Atmosphere
- Biosphere
- Hydrosphere
- Geosphere
- Earth is a dynamic planet
- Has changed continuously since its origin
- But we can look at processes happening today to understand processes of the past - uniformitarianism
