Across
- 1. The turning of the Earth on its imaginary axis
- 2. Power generated by the movement of air
- 3. Fuel produced from renewable resources
- 6. Energy generated by the sun
- 8. Energy generated by moving water
- 12. The periodic rise and fall of oceans under the gravitational pull of the moon
- 13. The different shapes of the moon as we see it from Earth during the time that the moon revolves around the Earth
- 14. The curved path around an object, such as the path a planet follows around the sun
- 15. The sun, eight planets, and the other objects that orbit the sun in a predictable manner
- 18. The ability for doing work
- 19. The total or partial covering up of one celestial body by another
Down
- 1. A resource that nature produces that can be replaced in a short period of time
- 4. Resources that nature cannot replace quickly enough to meet people's needs
- 5. The natural force of attraction between any two objects, such as the Earth and Sun, which gets stronger the bigger the object
- 7. Energy generated by heat from the interior of the Earth
- 9. The action by a celestial body of going round a fixed course
- 10. A form of energy that is transferred by a difference in temperature
- 11. A bowl shaped depression with a raised rim, formed by the impact of a meteorite
- 16. One of the four periods of the year
- 17. A natural satellite that orbits the Earth that shines by the Sun's reflected light