| A | B |
| phase | one of the different apparent shapes of the moon as seen from Earth |
| eclipse | the partial or total blocking of one object in space by another |
| solar eclipse | moon blocks our view of the sun by coming directly between the sun and Earth |
| umbra | darkest part of the moon's shadow |
| penumbra | part of the moon's shadow that surrounds the darkest part |
| lunar eclipse | Earth blocks sunlight from reaching the moon when it moves directly between the sun and the moon |
| tide | rise and fall of ocean water |
| neap tide | time when the difference between high tide and low tide is least |
| spring tide | time when there is the greatest difference between high and low tide |
| telescope | instrument used to see distant objects |
| maria | dark flat areas on the moon |
| craters | large round pits on the moon's surface |
| meteoroids | chunks of dust or rock from space |