Celestial Wonders

Across

1. Noble gas found in the atmosphere

4. Vast universe beyond our planet

7. Cloud of gas and dust in space

9. Massive system of stars and planets

10. Celestial object with a glowing tail

11. Astrological circle divided into twelve signs

12. Relating to stars or excellence

Down

2. Shooting star streaking through sky

3. North Star guiding sailors at night

5. Path followed by a satellite around a planet

6. Ending added to a root word

8. All existing matter and space