Across
- 3. What happens to the orbital period when planets are further from the Sun.
- 7. A unit of distance equal to the distance that light travels in one year.
- 9. A cloud of dust an gas from which stars form.
- 10. The name give to a group of stars that make a pattern in the night sky.
- 11. The force that pulls gas and dust together when a star is formed.
- 13. The time taken for a planet to complete one orbit of the Sun.
Down
- 1. The name of the robotic probe launched in 1977 and is now furthest from Earth.
- 2. The largest planet in the Solar System.
- 4. The two times in a year when day and night are equal length.
- 5. The second furthest planet from the Sun.
- 6. Made up of many stars; ours is called the Milky Way.
- 8. A word that describes the four planets closest to the Sun.
- 12. What the planets and moons do to sunlight that allows us to see them.