Across
- 4. when the universe started
- 8. a large spherical celestial body
- 9. a vast, interstellar cloud of dust
- 10. an invisible force of attraction
Down
- 1. a natural satellite of the Earth
- 2. a luminous explosion of a star
- 3. the planet that crashed into the early Earth
- 5. a huge collection of planets and stars
- 6. a curved repeating path of a planet
- 7. a luminous sphere of hot gas