Features Of The Universe

4. The change in wave frequency during the relative motion between a wave source and its observer
7. A hot ball of glowing gases at the heart of our solar system
8. A giant cloud of dust and gas in space
9. It may exist in potential, kinetic, thermal, helectrical, chemical, nuclear, or other forms
11. Radio waves, microwaves, infrared, visible, ultraviolet, X-ray and gamma radiation are all different forms of light
12. Any massive self-luminous celestial body of gas
15. The boundless three-dimensional extent to which objects and events have relative position and direction
16. Millenium- 1000 years Century-100 years decade-10 years
17. Lumps of rock or iron that orbit the sun
18. The distance light travels in one year
19. Where gravity and density are infinite and space-time extends into infinity

1. Highly magnetized rotating compact star
2. the substance or substances of which any physical object consists or is composed
3. Smaller than a star and doesn't give off light
5. Sprawling systems of dust, gas, dark matter
6. An individual form of life that is capable of growing and reproducing, and have one or more cells.
10. A very large star of high luminosity and low surface temperature
12. A powerful and luminous stellar explosion
13. A small piece of anything
14. How astronomers explain the way the universe began