| A | B |
|---|
| rotation | One of the two movements of the Earth. |
| revolution | Another movement of the Earth. |
| 24 hours | period of one of Earth's rotations. |
| one year | period of one of Earth's revolutions. |
| winter, spring, summer, and fall. | seasons of the Earth. |
| summer solstice | longest day of the year. |
| winter solstice | shortest day of the year. |
| vernal equinox | when spring starts. |
| autumnal equinox | when autumn begins. |
| moon | dry, airless, and barren world. |
| highlands | mountain ranges on the moon. |
| maria | smooth lowland plains on the moon. |
| new moon | when the moon is not visible. |
| full moon | when the moon is fully visible. |
| waxing moon | when lighted area of the moon appears to grow larger. |
| waning moon | when the lighted area of the moon appears to grow smaller. |
| solar eclipse | when a new moon comes between the sun and the Earth. |
| lunar eclipse | when the Earth comes between the sun and the full moon. |
| spring tide | high tides higher than normal, full and new moon phases. |
| neap tide | high tides lower than normal,first and last quarter phases of the moon. |
