| A | B |
|---|
| axis of rotation | an imaginary line about which Earth turns |
| revolution | the motion of one object around another |
| season | patterns of temperature changes and weather trends over the course of a year |
| equinox | occurs when sunlight shines equally on the northern and southern hemispheres |
| solstice | occurs when the amount of sunlight is greatest in one hemisphere |
| mare | a dark area on the Moon |
| eclipse | occurs when a shadow makes the Sun or the Moon seem to grow dark |
| umbra | the darkest part of the shadow |
| penumbra | a spreading cone of lighter shadow around the umbra |
