Across
- 3. To process materials so they can be used again.
- 4. Turning of Earth on its axis.
- 5. The force of air pushing down on Earth.
- 6. The layer of gases surrounding Earth.
- 8. A bowl-shaped hole on the Moon or a planet.
- 9. The spinning pointer that shows wind direction.
- 10. To make less waste.
- 11. The imaginary line Earth spins around.
- 13. Rain made acidic by pollution.
- 16. Waste made from decayed plants that helps soil.
- 17. Dirty or harmful substances in the environment.
- 19. Earth's journey around the Sun.
- 20. To bounce light back from a surface.
- 22. Water vapor in the air.
Down
- 1. Instrument used to measure wind speed.
- 2. An object moves around another object.
- 7. A scientific guess about what may happen.
- 8. Protecting natural resources.
- 12. Everything around us, including living and nonliving things.
- 14. To use something again instead of throwing it away.
- 15. A line around the middle of Earth.
- 18. One half of Earth.
- 21. The outside layer of an object.