| A | B |
|---|
| Sphere | three dimensional round shape |
| Axis | imaginary line around which Earth spins |
| Rotation | spinning on an axis |
| Revolution | traveling around in orbit |
| Ellipse | not quite circular path of travel |
| Magnetic axis | imaginary line between magnetic North and Magnetic South poles |
| Solstice | the day the sun reaches its Northernmost/Southernmost point |
| Equinox | day and night are equal lengths |
| Moon phases | changes in appearance of the moon due to the moon's orbit around Earth |
| New moon | phase where moon appears dark |
| Waxing | when the lit part of the moon is becoming more visible from night to night |
| Waning | when the lit part of the moon is becoming less visible from night to night |
| Crescent moon | phase where only a sliver of the moon is lit |
| Full moon | phase where the entire lit side of the moon is visible |
| Gibbous moon | phase where over half of the lit side of the moon is visible |
| Lunar eclipse | the moon is darkened due to passing through Earth's shadow |
| Solar eclipse | part of the Earth is darkened due to passing through the moon's shadow |
| Umbra | darkest area of a solar eclipse |
| Penumbra | lighter area of a solar eclipse |
| Maria | large plains caused by volcanic eruption |
