Across
- 2. when the northern hemisphere is tilted toward the sun, it is this season in North America
- 4. gas that gives Neptune and Uranus their blue-green color
- 6. Earth's spinning on its axis that causes day and night
- 7. shape of Earth's orbit
- 9. planet that rotates on its side
- 11. sometimes called Earth's twin
- 15. often called the red planet
- 16. planet with an orbit that intersects the orbit of the dwarf planet Pluto
- 17. length of time for Earth to orbit the sun once
- 18. planet with little or no atmosphere because the solar winds blow it away
- 20. an orbit around the sun
- 21. all outer planets are composed mainly of this type of matter
- 22. number of moons orbiting Mercury and Venus
- 23. when the northern hemisphere is tilted away from the sun, it is this season in North America
- 24. space object that was reclassified as a dwarf planet in 2006
Down
- 1. largest planet in the solar system
- 3. this planet has the largest volcano in the solar system, Olympus Mons
- 5. length of time for Earth to spin on its axis once
- 7. planet with an atmosphere that consists mainly of nitrogen and oxygen
- 8. name of Earth's moon
- 10. planet with the largest ring system
- 12. where many asteroids are found; separates the inner and out planets
- 13. contains over 99% of the mass of the solar system
- 14. huge storm on Jupiter
- 19. a natural satellite