- The axis of the earth is inclined at an angle of 23.5° to the plane of its orbit
- This inclination helps us to mark the following important parallels on the globe:
- The Tropic of Cancer at 23.5° N
- The Tropic of Capricorn at 23.5° S
- The Arctic Circle at 66.5° N
- The Antarctic Circle at 66.5° S
- The equator at 0° , the North Pole at 90° N and the South Pole at 90° S are also important parallels