| A | B |
|---|
| rotation | the spinning motion of an object on its axis. It is the reason for day and night because it takes 24 hours for the Earth to make one complete rotation |
| revolution | The movement of an object around another object or point. It takes about 365 days (one year) for Earth to make one revolution around the Sun. |
| orbit | the path a planet, moon or other object takes around another |
| waxing | growing phase of the moon from New Moon to Full Moon |
| waning | illuminated part of the moon is decreasing |
| crescent moon | less than 50% of the moon that is facing the Earth is illuminated |
| quarter moon | 50% of the moon that is facing the Earth is illuminated |
| gibbous moon | more than 50% of the moon that is facing the Earth is illuminated |
| full moon | 100% of the moon is illuminated |
| new moon | the moon is not illuminated |
| Mercury | the planet closest to the moon |
| Venus | the second planet from the sun |
| Earth | the third planet from the sun |
| Mars | the fourth planet from the sun |
| Jupiter | the fifth planet from the sun |
| Saturn | the sixth planet from the sun |
| Uranus | the seventh planet from the sun |
| Neptune | the furthest planet from the sun |
| axis | the imaginary pole that the Earth rotates around |
| constellation | a grouping of stars forming a recognizable pattern |
| Sun | the star closest to Earth |
| Polaris | the North Star |
| Ursa Major | Greater Bear; or Big Dipper |
| Ursa Minor | Lesser Bear; or Little Dipper |
| Orion | constellation near the equator |
| star | any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources. |
| astrolabe | the oldest of the tools used for astronomical measurements (that we studied) |
| sextant | used in navigation to measuring the angular distance between the horizon and celestial bodies |
| compass | navigational tool that indicated the direction to north, south, east and west |
| telescope | an instrument to make distant object seem closer |
