Chapter 30 - Galaxies

1234567891011121314151617181920212223242526272829303132
Across
  1. 4. The theory that the universe began as a hot, dense point and has been expanding.
  2. 6. Faint radiation left over from the early universe.
  3. 8. The small cluster of galaxies that includes the Milky Way.
  4. 9. The flattened region of a spiral galaxy that contains stars, gas, and dust.
  5. 13. A galaxy with a flat disk and spiral arms (example: the Milky Way).
  6. 16. Gas and dust found between stars within a galaxy.
  7. 17. An extremely bright and distant active galactic nucleus powered by a supermassive black hole.
  8. 18. The distance light travels in one year (about 9.46 trillion km).
  9. 20. The observation that the farther away a galaxy is, the faster it moves away from us.
  10. 22. A spherical collection of old stars orbiting the halo of a galaxy.
  11. 25. A huge system of billions of stars, gas, dust, and dark matter held together by gravity.
  12. 27. The spiral galaxy that contains our solar system.
  13. 28. The stretching of light toward longer (red) wavelengths as objects in space move away from us.
  14. 29. A rapid expansion of the universe shortly after the Big Bang.
  15. 30. A massive black hole found at the center of most galaxies.
  16. 31. A spiral galaxy with a bar-shaped group of stars across its center.
  17. 32. An outdated theory that proposed the universe has always existed and remains constant.
Down
  1. 1. A galaxy with no definite shape.
  2. 2. A round or oval-shaped galaxy with mostly older stars and little gas or dust.
  3. 3. The study of the origin, structure, and future of the universe.
  4. 5. The spherical region surrounding a galaxy, containing old stars and globular clusters.
  5. 7. The dense, central region of a galaxy.
  6. 10. The estimated time since the Big Bang (about 13.8 billion years).
  7. 11. Regions in a spiral galaxy where stars are actively forming.
  8. 12. The tightly packed group of stars at the center of a spiral galaxy.
  9. 14. The supermassive black hole at the center of the Milky Way.
  10. 15. A group of galaxies bound together by gravity.
  11. 19. Invisible matter that does not emit light but whose gravity affects galaxies.
  12. 21. A loosely grouped collection of young stars in a galaxy’s disk.
  13. 23. The idea that galaxies are moving away from each other over time.
  14. 24. A mysterious force causing the expansion of the universe to speed up.
  15. 26. A galaxy that gives off unusually large amounts of energy from its center.