1. Tilt of the Earth’s Rotational Axis
The Seasons
Tilt of the Earth’s Rotational Axis

2. Spin Axis – Rotational Axis
Rotational Axis tilted by ~ 23.5 degrees with respect to orbital plane (ECLIPTIC)

3. Tilt is cause of Seasons
Winter in Northern Hemisphere – notice Artic is in complete darkness 66.5 degrees

4. Seasonal Changes
Not drawn to scale – 66.5 degrees Artic circle or Ant Artic circle

5. Diurnal Motion from Different Latitudes
North Pole, Equator, Kitt Peak 31 degrees

6. Diurnal Motion of Sun at different times of the Year from ~40 degrees
Vernal Equinox, Autumnal Equinox, Summer Solstice, Winter Solstice

7. Summer and Winter
Direct and indirect sunlight