Across
- 4. element that forms in the cores of massive stars causing fusion to stop
- 6. calculated as mass divided by volume
- 7. forms when a massive star dies; intense gravity that not even light can escape
- 9. force of attraction in the universe
- 12. model of the solar system that places the sun in the center
- 13. anything that has mass and takes up space
- 16. phase of the moon in which the entire lit side is facing Earth
- 17. super dense star that forms when a massive star dies
- 19. theory that explains the formation of the universe
- 21. relatively cool area on the surface of the sun
- 22. the Sun's visible layer
- 23. classification of stars in which most stars are found
- 24. a collection of billions of stars held together by gravity
- 25. created the three laws of planetary motion
- 26. ______ magnitude is how bright a star actually is
Down
- 1. measurement of distance based on the distance that light can travel in a year in the vacuum of space
- 2. where nuclear fusion occurs in the sun
- 3. the only EM wave that humans can see
- 5. ______ magnitude is the how bright a star appears from Earth
- 8. EM wave with the longest wavelength
- 10. theory that explains the formation of the solar system
- 11. model of the solar system that places Earth in the center
- 14. EM waves are these types of waves
- 15. a collection of stars that make a picture used to map the night sky
- 18. the change in wavelength based on the motion of an object relative to the position of the observer is called the ____ effect
- 20. EM wave with the highest energy