Motion of the Earth

1. Motion of the Earth Chapter 2.1 Day and Night Earth’s Seasons

2. I. The Earth Moves in two different ways. • A. Rotation- The Earth rotates on its axis. • 1. The Earth spins one time every 24 hours. • 2. The rotation of Earth causes night and day. • 3. The Earth rotates counter clockwise.

3. B. The Earth revolves around the Sun. • 1. Earth circles the Sun once a year or every 365 ¼ days. • 2. The Earth circles the Sun in an elliptical orbit. (big oval). • 3. Revolution is involved in causing the seasons on Earth.

4. Seasons on Earth are caused by its revolution and tilt. A. The Earth is tilted 23.5 from its orbit. B. The North Pole faces the same way, into space, all year.

5. C. There are four seasons caused by Earths tilt. • 1. September equinox - Equal amounts of sun light hit the Northern and Southern hemispheres. This is fall in the North. • 2. December Solstice- The north pole is tilted away from the Sun, causing Summer in the southern hemisphere.

6. 3. March equinox- Equal amounts of sun light hit the Northern and Southern hemispheres. This is fall in the south. This is Spring in the North. • 4. June Solstice- The north pole is tilted towards the Sun, causing Summer in the North.