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