1. What are the motions of the Earth?

2. Earth and the Moon in Space The Earth and the moon are part of the sun’s planetary system. Pulled by the sun’s gravity, the Earth-moon system revolves or travels in a closed path around the sun. It is inertia that keeps the Earth in motion around the sun.

3. Earth in Space As Earth orbits the sun, it rotates or spins on its axis. The axis is an imaginary line that passes through Earth’s center and its North and South Poles. Earth’s axis is tilted about 23 ½ °.

5. Earth’s Rotation The North Pole of Earth always points toward Polaris or the North Star. It is the brightest and last star of the Little Dipper.

6. Earth’s Rotation Because of the Earth’s counterclockwise rotation, the Sun appears to rise in the East and set in the West. The Sun’s motion is East to West.

8. The Length of the Day Earth’s rotation results in day and night. When a location on Earth faces the sun, it is day in that place. When that location faces away from the sun, it is night. A day is defined as the time that it takes a planet to rotate once on its axis.

9. Earth’s Revolution A revolution is the movement of a planet or other body orbiting another body. One complete revolution of the Earth around the Sun takes 365 ¼ days.

10. What is the difference between orbit, revolution, and rotation? A planet rotates on its own axis and revolves around the sun in a path called an orbit.

11. What causes the seasons?

12. The tilt of the Earth is responsible for the seasonal differences we see and feel throughout the year.

15. Solstices and Equinoxes Spring Equinox ~ March 21 Summer Solstice ~ June 21 Fall Equinox ~ September 22 Winter Solstice ~ December 21 The dates of the equinoxes and solstices are only approximate dates. The actual length of a year is about 365 ¼ days. We have to add an extra day to a year every four years to keep the seasons synchronized with the Earth’s revolution (leap year).