1. UNIT 7.3 THE EARTH

2. The movement of the Earth Revolves around the Sun. Its orbit is an ellipse. Orbit time: 365 days, and 6 hours. Six hours every year make one more day in our calendar every four years, February the 29th. It is called leap year.

3. The rotation of the Earth The Earth is a rotating sphere. It rotates on an invisible axis which passes through the two poles. Each rotation takes 24 hours. Therefore; when it is day in one half, it is night in the other. The sun always rises in the east and sets in the west.

4. The seasons The Earth’s axis is not vertical. It is tilted 20 degrees. This inclination produces seasons. When one hemisphere receives light straightly (summer) The other one receives light with inclination (winter)

6. Comets Small celestial bodies made up of dust and rocks. They have bright tails made up of water vapour. When they come close to the Sun we can see them.

7. True or false? Copy and correct the wrong ones. There are exactly 365 days in a year. ____. The Earth rotates on its own axis. ____ It takes twelve hours to complete this rotation. ___ The Sun rises in the west and sets in the east. ____. The Earth’s axis is slightly tilted. ____ Comets have bright tails which point toward the Sun. _

8. There are exactly 365 days in a year. There are 365 days and 6 hours in a year. The Earth rotates on its own axis. T It takes twelve hours to complete this rotation. It takes ttwenty-four hours to complete this rotation The Sun rises in the west and sets in the east. The Sun rises in the east and sets in the west The Earth’s axis is slightly tilted. T Comets have bright tails which point toward the Sun. Comets have bright tails which point away from the Sun