Across
- 2. Large grouping of stars, planets, and dust
- 4. Element containing one proton and one electron
- 10. Brightness of a star
- 14. Primary substance that makes up matter
- 15. Explosion of a massive star
- 16. A self luminous celestial body consisting of a mass of gas
- 17. Point of an orbit where the celestial body is farthest from the sun
Down
- 1. Unit of length equal to the distance that light travels
- 3. Theory that states the universe began as a small point that expanded
- 4. The lightest noble gas
- 5. point in the ellipse that help determines the shape
- 6. Curved path followed by a satellite as it revolves an object in space
- 7. Following the path of an ellipse
- 8. Range of light waves emitted by a celestial body
- 9. Point closest to the sun in the orbit of a celestial body
- 11. All space and the matter space contains
- 12. Device that measures different wavelengths of electromagnetic radiation
- 13. Distribution of energy in wavelengths in a system