| A | B |
|---|
| a round, three-dimensional object | sphere |
| an imaginary vertical line around which Earth spins | axis |
| the spinning of Earth on its axis | rotation |
| Earth's yearly orbit around the Sun | revolution |
| an elongated, closed curve | ellipse |
| occurs when the sun is directly above Earth's equator | equinox |
| the day when the Sun reaches its greatest distance | solstice |
| the different forms that the moon takes in its appearance from Earth | moon phase |
| occurs when the moon is between Earth and the Sun | new moon |
| more of the illuminated half of the Moon can be seen | waxing |
| half of the lighted side of the Moon | first quarter |
| when all of the Moon's surface reflects light | full moon |
| describes the phase following a full moon as the visible lighted side of the Moon grows smaller | waning |
| when half of the side facing Earth is lighted | third quarter |
| occurs when the Moon moves directly between Earth and the Sun | solar eclipse |
| occurs when Earth passes between the Sun and Moon | lunar eclipse |
| dark, flat regions of ancient lava on the Moon | maria |
| the depression left behind by an object striking the Moon | impact basin |
| the path taken by an object revolving around another | orbit |
| portion of the interior of a moon lying between the crust and core | mantle |
| space object orbiting the Sun formed from dust and rock particles mixed water, methane, and ammonia | comet |
