Solar System

1234567891011121314
Across
  1. 3. surface is made of water ice and so it reflects 5.5 times the sunlight than our Moon does
  2. 4. the age is 13.6 billion years (and counting)
  3. 6. the fast is planet, zipping around the Sun every 88 Earth days
  4. 7. estimated to contain between 1.1 and 1.9 million asteroids larger than 1 kilometer (0.6 miles) in diameter, and millions of smaller ones.
  5. 10. the largest of Pluto's five moons
  6. 12. A day on it 153 hours
  7. 14. it spins slowly in the opposite direction from most planets
Down
  1. 1. makes a complete orbit around the Sun (a year in Martian time) in 687 Earth days
  2. 2. the biggest planet
  3. 5. one of the largest structures in our solar system
  4. 6. the earth's natural satellite
  5. 8. the earth's biggest heat source
  6. 9. the second-shortest day in the solar system
  7. 11. is the only planet in our solar system not visible to the naked eye
  8. 13. the first planet found with the aid of a telescope.