Across
- 2. A powerful and luminous stellar explosion
- 3. Smaller than a star and doesn't give off light
- 7. Millenium- 1000 years Century-100 years decade-10 years
- 9. How astronomers explain the way the universe began
- 10. The boundless three-dimensional extent to which objects and events have relative position and direction
- 12. the substance or substances of which any physical object consists or is composed
- 14. The distance light travels in one year
- 16. Where gravity and density are infinite and space-time extends into infinity
- 17. Any massive self-luminous celestial body of gas
- 18. A hot ball of glowing gases at the heart of our solar system
Down
- 1. Highly magnetized rotating compact star
- 4. A giant cloud of dust and gas in space
- 5. A very large star of high luminosity and low surface temperature
- 6. The change in wave frequency during the relative motion between a wave source and its observer
- 8. Radio waves, microwaves, infrared, visible, ultraviolet, X-ray and gamma radiation are all different forms of light
- 11. It may exist in potential, kinetic, thermal, helectrical, chemical, nuclear, or other forms
- 13. An individual form of life that is capable of growing and reproducing, and have one or more cells.
- 15. Sprawling systems of dust, gas, dark matter