ANSWERS  

1. Sputnik 1

2. Laika the dog

3. Yuri Gagarin

4. The Apollo Project

5. USA

6. Pluto

7. Pioneer 10

8. Challenger

9. Skylab

10. 4 (Columbia, Endeavour, Discovery and Atlantis)

11. Canals

12. Challenger

13. Ceres

14. Hydrogen

15. A meteorite is a meteor that has landed

16. Saturn (divisions in the rings)

17. Haley?s Comet

18. Pluto

19. Neptune

20. Proxima Centuri