Across
- 2. huge rotating collection of gas, dust, and billions of stars, planets, and other celestial objects
- 4. large, round celestial object that travels around a star, dominates its orbit, and has the shape of a sphere
- 6. celestial object that orbits the Sun and has a spherical shape but does not dominate its orbit
- 8. extremely dense quantity of matter in space from which no light or matter can escape
- 9. darkening of a celestial object due to the positioning of another celestial object
- 11. the scientific study of what is beyond Earth
- 12. everything that exists, including all energy, matter and space
- 13. all of the phases of the moon
- 14. producing and giving off light
- 15. massive collection of gases held together by its own gravity and emitting huge amounts of light energy
- 16. chunk of ice and dust that travels in a very long orbit around the Sun
Down
- 1. any object that exists in space
- 3. approximately 150 million kilometres
- 5. the brightness of stars in the night sky as they appear from Earth
- 7. the brightness of stars as if they were all located 33 ly away from Earth
- 10. closed path of a celestial object as it travels around another celestial object