Across
- 3. - a rocky sphere that travels around a planet
- 4. - an object, diagram, or computer program that helps us understand
- 9. - when the Moon is completely dark
- 11. - something we observe to be similar over and over again
- 12. - the border between light and dark on the Moon
Down
- 1. - to shine light on an object and make it visible
- 2. by making it simpler or easier to see
- 5. - the relative size of things
- 6. - the sun, the planets that orbit the sun, and the other objects that orbit the sun
- 7. - the amount of time it takes for a planet to complete one orbit around a star or stars
- 8. - the shape of the illuminated part of the Moon as it appears from Earth
- 10. - the star that is the main source of light at the center of our solar system
- 13. - the nearly circular path a smaller object (like the Moon) travels around a larger object (like Earth)