| A | B |
|---|
| corona | the low-density cloud of gases surrounding the sun |
| crater | holes or bowl-shaped depressions on a moon or planet |
| ebb tide | the movement of tidal current away form the shore |
| elliptical | oval-shaped |
| equinox | either of the two times of the year when the number of hours of daylight and darkness are the same in both hemispheres; marks the first day of spring and fall; means equal night |
| flood tide | the tidal current associated with the increase in the height of the tide |
| lunar eclipse | an event which occurs when Earth blocks the light as it moves between the sun and moon |
| lunar month | the measure of time it takes for the moon to pass from one new moon to the next (29 days) |
| maria | lunar seas or plains on the moon |
| moon phase | the changing appearance of the moon which depends on the moon's position relative to the sun |
| orbit | the path of an object revolving around another object; to revolve in an orbit around another object |
| partial eclipse | an event which occurs when part of the sun is blocked out by the moon |
| penumbra | part of a shadow cast by an object in which light from the source is only partly blocked |
| revolve | to move around another heavenly |
| rotate | to spin on an axis |
| solar eclipse | an event which occurs when the moon passes between Earth and the sun |
| solstice | either of the two times a year when the sun is at its greatest apparent distance north or south of th equator; marks the first day of summer and winter |
| spring tide | tide that occures when the sun, moon, and Earth are in a straight line. |
| total eclipse | an event which occurs when the sun is completely blocked out by the moon |
| umbra | the part of a shadow cast by an object in which light from the source is completely blocked |
