Earth, Moon, And Sun

4. the border between light and dark on the Moon
5. to shine light on an object and make it visible
7. a moon phase in which the Moon is not visible from Earth
11. when the Moon is completely dark
13. the nearly circular path a smaller object (like the Moon) travels around a larger object (like Earth).
15. a moon phase that looks like a half-circle from Earth
17. the relative size of things
18. a planet outside our solar system
19. an object, diagram, or computer program that helps us understand something by making it simpler or easier to see

1. a moon phase that looks like less than half a circle from Earth
2. moon a moon phase that looks like more than half a circle from Earth
3. the star that is the main source of light at the center of our solar system
6. a rocky sphere that travels around a planet
8. a moon phase that looks like a full circle from Earth
9. something we observe to be similar over and over again
10. the amount of time it takes for a planet to complete one orbit around a star or stars
12. the sun, the planets that orbit the sun, and other objects that orbit the sun
14. phase the shape of the illuminated part of the Moon as it appears from Earth
16. a moon outside our solar system