6th Grade Science

3. The spinning motion of a planet or moon on its axis, causing day and night.
4. The different, changing shapes of the moon as seen from Earth, caused by the reflection of sunlight.
7. A force of attraction that pulls any two objects with mass toward each other.
8. The scientific study of stars, planets, moons, and all other objects in space.
9. An imaginary, tilted line that runs through the North and South Poles about which Earth rotates.
11. The solid, rocky part of Earth, including the crust, mantle, and core.
12. The part of Earth, including the air, land, and water, where all living things exist.
13. The time twice a year (March/September) when day and night are nearly equal in length because neither hemisphere is tilted toward the sun.
15. The process of breaking down rocks and minerals on Earth's surface by wind, water, or ice.

1. Tectonics The theory explaining the movement of large, solid plates that make up Earth's outer shell.
2. The Sun and all the planets, moons, asteroids, and comets that are held in orbit by the Sun's gravity.
5. All the water on Earth's surface, including oceans, lakes, rivers, and ice.
6. The layer of gases surrounding Earth that protects the planet and enables life.
10. The two days in a year (June/December) when the sun is farthest north or south of the equator, resulting in the longest or shortest day.
14. The curved path that an object, such as a planet or moon, takes as it revolves around another body in space.
16. The movement of one object around another object, such as Earth orbiting the Sun.