1. Space Cycles
Vocabulary

2. Axis
Imaginary line around which Earth spins, causing day and night, and that is drawn from the north geographic pole through Earth to the south geographic pole.

4. The Earth's axis is at an angle of 23.45°
Tilt
The Earth's axis is at an angle of 23.45°

6. Latitude
Imaginary lines that cross the surface of the Earth parallel to the Equator, measuring how far north or south of the Equator a place is located.

8. The curved path of the Earth around the Sun.
Orbit
The curved path of the Earth around the Sun.

10. Revolution The motion of Earth around the Sun.
One revolution takes about 365 1/4 days, or one year, to complete

12. Rotation The spinning of Earth on its axis. This causes day and night.
It takes 24 hours for Earth to complete one rotation .

14. Solstice
Time when the Sun reaches its greatest distance north or south of the equator, which occurs June 21 or 22 for the northern hemisphere (longest day of the year) and December 21 or 22 for the southern hemisphere (shortest day of the year).

16. Equinox
Twice-yearly time when the Sun is directly above Earth's equator and the length of day equals the length of night worldwide.