• Earth rotates on its own axis, and on an orbit around the sun
• The angle of its axis is the obliquity of earth (ranges from 22.1 and 24.5)

Eccentricity:

• How circular the earth's orbit around the sun is (between 0 and 1)
  • Perihelion - Closest to sun
  • Aphelion - Furthest from sun

Seasons:

• Exist because of obliquity
• The severity of seasons is influenced due to obliquity
  • The more the obliquity, the more extreme the seasons are
    • When the earth is tilted more towards the sun, each hemisphere receives more solar radiation during the summer
    • Larger angle tilts favor periods of deglaciation

Moon:

• Phases of the moon are caused by the angle between the earth, moon and sun

• The moon is a satellite
  • A satellite is a celestial body that revolves around another celestial body$^4$