| A | B |
|---|
| axis | An imaginary line that passes through Earth's center and the North and South poles, about which Earth rotates. |
| rotate | to spin on an axis |
| revolve | to move around a central point |
| orbit | The path of an object as it revolves around another object in space. |
| phase | One of the different shapes of the moon as seen from Earth. |
| eclipse | The partial or total blocking of one object by another. |
| solar eclipse | The blocking of sunlight to Earth that occurs when the moon is between the sun and Earth. |
| umbra | The darkest part of a shadow. |
| penumbra | The part of a shadow surrounding the darkest part. |
| lunar eclipse | The blocking of sunlight to the moon that occurs when Earth is directly between the sun and moon. |
| tide | The daily rise and fall of Earth's waters on shores. |
| satellite | Any object that revolves around another object in space. |
| crater | A round pit on the moon's or other surface, created by a force of impact. |
| maria | Dark, flat regions on the moon's surface. |
| crescent | Moon phase in which less than half of the Moon appears to be illuminated. |
| First Quarter | Moon phase in which exactly half of the Moon appears to be illuminated approimately 7-8 days following the New Moon. |
| Full Moon | Moon phase in which all of the Moon appears to be illuminated. |
| Gibbous | Moon phase in which more than one half of the Moon appears to be illuminated. |
| Illuminate | to brighten with light |
| New Moon | Moon phase in which none of the moon appears to be illuminated. |
| Third Quarter | Moon phase in which exactly half of the moon appears to be illuminated, approximately 21-22 days following the New Moon. |
| Waning | decreasing in size or amount of light (lit side of the moon appears on the left) |
| Waxing | increasing in size or amount of light (light appears on the right side of the moon) |
