| A | B |
|---|
| Revolution | Earth's movement around the sun. |
| Rotation | Earth's spinning that causes day and night |
| Axis | Imaginary line through the poles. The Earth spins around this. |
| Ellipse | Shape of the Earth's orbit around the sun |
| Sphere | Shape of the Earth. |
| Equinox | This occurs when the sun is directly over the equator. The entire globe experiences the same amount of daylight and nighttime hours. |
| Solstice | Occurs when the northern or southern hemisphere is tilted toward the sun |
| Lunar Eclipse | When Earth casts a shadow on the moon. |
| Solar Eclipse | When the moon moves between the sun and the Earth, blocking out the sun. |
| Waxing | The period of the moon phase when the moon appears to be growing in size. |
| Waning | The period of the moon phases when the moon appears to be shrinking in size. |
| 365 days | The amount of time it takes the Earth to travel around the sun. |
| 24 hours | The amount of time it takes the Earth to spin on its axis one time, causing day and night. |
| 27.3 days | The time it takes the moon to rotate and to revolve around the Earth. |
| New Moon | 1st phase of the moon cycle. The moon is not visible. |
| Waxing Crescent | Occurs right after the new moon. |
| 1st Quarter | Moon phase that occurs before the full moon. The observer can only see half of the lighted side of the moon. |
| Waxing Gibbous | Moon phase that appears before the full moon. The observer can see more than the 1st quarter phase. |
| Full Moon | The observer can see the entire half of the lighted moon. |
| Waning Gibbous | Moon phase that occurs right after the full moon. |
| 3rd Quarter | Moon phase that occurs after the full moon. The observer can only see half of the lighted side of the moon. |
| Waning Crescent | Moon phase that occurs right before the new moon. |
