Planet for Kids Quiz 1. Which planet is the fastest planet? 2. Which planet is the most likely candidate for a future human habitat? 3. Which planet is named after the Roman goddess of beauty? 4. How many years does it take for Uranus to orbit once around the sun? 5. Which planet is the hottest planet of the solar system? 6. Which planet is named after the Roman god of the sea? 7. How many years does it take for Neptune to orbit once around the sun? 8. Which spacecraft is currently observing Jupiter? 9. Which is the second largest moon in our solar system? 10. 11. 12. What is the name of the highest peak on Mars? Which planet is covered largely by water? Which planet is known for the "Great Red Spot"?