1. THE EARTH IN SPACE
THE SEASONS
The Earth in Space

2. The Seasons Earth at winter Earth at Spring Earth at fall
Earth at Summer

3. The cause of the seasons on Earth
Please note: the North Pole always points toward the North Star (Polaris)

4. Causes of seasons on a Earth
1. The tilt of Earth’s (or any planet’s) axis
2. Place or position of the Earth (or any planet) as it orbits around the Sun

5. The effects of the 23.5° tilt on Earth
The tilt of the Earth’s axis and the position of Earth in its orbit affect the angle that the sunlight strikes the Earth
Please draw this diagram

6. The effects of the 23.5° tilt
The tilt of the Earth’s axis and the position of Earth in its orbit affect the angle that the sunlight strikes the Earth
Please draw this diagram

8. Position of N. Hemisphere
Solstice
Summer Solstice - the first day of Summer
* Northern Hemisphere June 21 or 22
* Southern Hemisphere December 21 or 22
Winter Solstice - the first day of winter
* Northern hemisphere December 21 or 22
* Southern Hemisphere June 21 or 22
Position of N. Hemisphere
at Summer Solstice
Position of S. Hemisphere at
Winter Solstice

10. Equinox Equinox : a nearly equal number of daylight and dark hours
Vernal Equinox the nearly equal number of daylight and nighttime hours when the Earth is positioned in its orbit exactly half way between summer and winter
Atumnual Equinox the nearly equal number of daylight and nighttime hours when the Earth is positioned in its orbit exactly half way between summer and winter

11. Review What is rotation and how does it affect Earth
What is revolution and how does it affect Earth
Be able to compare and contrast rotation and revolution
What causes the seasons and why distance is not used to determine the seasons
Explain why seasons are opposite between the Northern and Southern Hemisphere
Understand the terms Solstice and Equinox
Explain why and how the Tropics are determined
Explain how the Arctic and Antarctic circles are determined