Across
- 2. system what system contains a sun and planets
- 3. BELT Between Mars and Jupiter
- 5. My teacher calls himself
- 7. invented by Dirac
- 9. the program of human traveled on the moon
- 11. how many humans walked on the moon
- 13. combination of atoms
- 15. Milky Way the white band in the sky is made of stars
- 16. closet planet to the sun
- 18. they have a very regular organized structure
Down
- 1. found in the nucleus of an atom
- 3. the topic about planets, black holes, galaxies, big bang, and quasars
- 4. big and light, negative charge
- 6. a position was the first example of it
- 8. the planet which we are living
- 10. hundreds of billions of it and lots are spiral
- 12. the measure of distance between planets
- 14. by volume it is mostly empty
- 17. Dwarf what will our sun eventually become
- 19. the earth gets most energy from it