| A | B |
|---|
| Precession | slow wobble of the Earth's axis caused mainly by the gravitational pull of the sun, moon, and other planets. |
| Nutation | small wobble in angle of Earth's tilt. |
| Barycenter | The point between two objects where they balance each other |
| Rotation | The earth rotates on its axis |
| Revolution | The Earth revolves around the sun |
| Spring Tide | Tidal Range is greater when the earth, sun, and moon are aligned during new moon and full moon phases. |
| Neap Tide | Tidal Range is smaller when the earth, sun, and moon for a right angle during the 1st quarter and 3rd quarter moon phases. |
| Fusion | Process in a star's core in which lightweight hydrogen nuclei combine into heavier nuclei |
| Electromagnetic waves | Energy is transported by waves in the world around us. The waves are caused by a vibration in matter, gas, liquid, or plasma |
