Across
- 2. Which planet do scientists think formed first?
- 5. The rocky planets are made of chunks of rock and________
- 7. Just like humans and animals which may move from one place to another, planets moved closer and further from the Sun in their early lifetime-we call this___________
- 9. What do we call planets which orbit other stars?
- 11. Our solar system is thought to be about 4.5 ____ years old
- 13. What are the rocky leftover pieces of rock in the Solar System called?
- 14. Which object was the first to form in the solar system?
- 15. Which planet is spinning in the opposite direction to all the others?
Down
- 1. Scientists think that perhaps water was brought to the Earth by___________
- 3. What are large pieces/the building blocks of planets called?
- 4. Our sun formed from a huge cloud of material which was pulled together and planets are kept in orbit around the Sun. Which force is responsible for both these things?
- 6. Jupiter swallowed up lots of materials around it-which planet is smaller in size than expected as a result?
- 8. Objects which were captured by planets and now orbit around them are called ___________
- 10. There are two ice giant planets. Uranus is one, which is the other?
- 12. Which planet was knocked onto its side by an impact?