moon, earth, sun

12345678910111213141516171819
Across
  1. 4. an object, diagram, or computer program that helps us understand something by making it simpler or easier to see
  2. 5. a rocky sphere that travels around a planet
  3. 6. a planet outside our solar system
  4. 8. the amount of time it takes for a planet to complete one orbit around a star or stars
  5. 9. a moon phase that looks like more than a half a circle from Earth
  6. 11. the relative size of things
  7. 13. to shine a light on an object and make it visible
  8. 15. a moon phase that looks like a half-circle from Earth
  9. 16. the nearly circular path a smaller object(like the moon)travels around a larger object(like Earth)
  10. 17. a moon phase that looks less than half circle from Earth
  11. 19. a moon phase in which the moon is not visible from Earth
Down
  1. 1. the border between light and dark on the Moon
  2. 2. a moon outside our solar system
  3. 3. a moon phase that looks like a full circle from Earth
  4. 7. the shape of the illuminated part of the moon as it appears from Earth
  5. 10. the sun, the planets that orbit the sun, and other objects that orbit the sun
  6. 12. when the moon is completely dark
  7. 14. something we observe to be similar over and over again
  8. 18. the star that is the main source of light at the center of our solar system