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Seasons
Why we have seasons?
| Term | Definition |
|---|---|
| Rotation | The spin of an object around its axis |
| Rotation axis | The line on which an object rotates |
| Orbit | The path an object follows as it moves around another object |
| Revolution | The orbit of one object around another object |
| Solstice | When Earth’s rotation axis is tilted directly toward or away from the Sun |
| Equinox | When the Earth rotation axis is tilted neither forward nor away from the Sun. |
| Phase | The lit part of the Moon or planet that can be seen from Earth. |
| Waxing phase | Phases of the Moon during which more of the Moon’s near side is lit each night. |
| Waning phase | Phases of the Moon during which less of the Moon’s near side is lit each night. |
| Umbra | The central, darker part of a shadow where light is totally blocked. |
| Penumbra | The lighter part of a shadow where light is partially blocked. |
| Solar eclipse | An occurrence during which the Moon’s shadow appears on Earth’s surface. |