Seasonal Changes Lesson Introduction

Day & Nights The Earth travels around the sun in an oval shaped path called an orbit. It takes 365 1/4 days for it to complete one revolution or journey around the sun. The Earth spins around on its axis– an imaginary line running through its North & South poles.

What is a season? A season is one of the four natural parts of the year. Winter Spring Summer Fall

Why do we have seasons? The changes of the seasons are caused by the changing position of the earth on its axis. During the winter months in North Carolina, our part of the earth is slanted away from the sun. During the summer months in North Carolina, our part of the earth is slanted toward the sun.

The Earth spins on its axis. An axis is an imaginary straight line that goes through an object – like a planet. The object (planet) spins around the axis. Let's try to picture this! Here is the imaginary straight line. Now let’s put it through the Planet! Do you see the planet spinning around the axis? That is almost right! tilted 23.5 degrees. Our Planet is Watch This! That’s better!

Understanding the Seasons It’s all in the tilt Summer: - Earth is tilted toward the sun, we get a more direct light, so it’s warmer Winter: - Earth is tilted away from the sun, we get slanted light, so it’s cooler No tilt means 1 Season!

Understanding Summer and Winter Summer in the North Winter in the North ☺ ☹ S ☺ ☹ U night day N South South From summer to winter earth revolves half-way around Sun

Energy distribution from Sun slanted hit large area (cooler) U direct hit small area (warmer) N

Seasons During the year, days or nights might seem longer because of the Earth’s tilt on its axis. The Earth’s tilt/orbit cause changes in temperature.

Special Days Vernal Equinox March 20 Winter Solstice Dec 21 Summer June 21 Autumnal Equinox Sept 22 Vernal Equinox March 20

Illustration Draw a picture showing the Earth’s position as it revolves around the sun. Label each season.