Across
- 4. boundary between the solar system and interstellar space
- 5. most volcanically active world in the solar system
- 6. largest natural satellite in the inner solar system
- 10. dwarf planet that lives in the asteroid belt
- 12. not visible to the naked eye
- 15. this dwarf planet is the most massive but only second largest
- 16. has a retrograde orbit around its planet
- 17. the most heavily cratered object in the solar system
- 19. cloud of comets distantly orbiting the Sun
- 20. densest planet
- 21. opportunity’s home
- 22. this icy moon has a vast ocean beneath its surface
- 24. has an exosphere but no true atmosphere
- 25. our favorite dwarf planet since 2006
Down
- 1. this moon is larger than Mercury
- 2. Mars’s smaller moon
- 3. location of objects beyond Neptune’s orbit
- 6. Uranus moon with canyons deeper than Earth’s
- 7. larger volume than every other planet combined
- 8. between mars and jupiter
- 9. greenhouse gases make it as hot as an industrial oven
- 11. star
- 13. mars moon that is slowly getting closer to the red planet
- 14. it rains methane here
- 17. largest known natural satellite in comparison to its host planet
- 18. could float on water
- 23. has a 98° tilt