1. Galaxies of Stars

2. irregular elliptical spiral

3. Instructions: Copy the following notes on each slide and then underline the important terms shown on the following slide.

4. The Milky Way The Sun, planets, and other objects in the solar system are part of a larger system, the Milky Way galaxy.

5. The Milky Way The Sun, planets, and other objects in the solar system are part of a larger system, the Milky Way galaxy.

7. Our galaxy contains hundreds of billions of stars, and the gas and dust they are formed from, all held together by their mutual gravitational attraction to one another.

8. Our galaxy contains hundreds of billions of stars, and the gas and dust they are formed from, all held together by their mutual gravitational attraction to one another.

9. Gravity – the force of attraction one object in the universe has for every other object in the universe.

10. The stars and nebula are arranged in the shape of a disk 100,000 light years across. There are great arms of stars, dust, and gas that spiral out from a central bulge.

11. The stars and nebula are arranged in the shape of a disk 100,000 light years across. There are great arms of stars, dust, and gas that spiral out from a central bulge.

12. Star – a collection of gas that shines from nuclear fusion. The Sun is a star. Nebula – an interstellar cloud of gas and dust. Light year – the distance light travels in one year.

13. Looking edge on it would appear some what like a fried egg. Viewed from above it has the appearance of a pinwheel. This type of galaxy is classified as a “spiral”.

14. Looking edge on it would appear some what like a fried egg. Viewed from above it has the appearance of a pinwheel. This type of galaxy is classified as a “spiral”.

16. Our solar system is located near the outer edge of our galaxy in one of the spiral arms. From Earth, our galaxy appears as a hazy band of light across the night sky, thus the ancient name of “Milky Way”.

17. Our solar system is located near the outer edge of our galaxy in one of the spiral arms. From Earth, our galaxy appears as a hazy band of light across the night sky, thus the ancient name of “Milky Way”.

20. Copy the question on each slide (not choices). Refer to your notes to help you select the best choice that answers the question. When the correct answer is confirmed, copy it.

21. Make sure to copy the questions and answers as accurately as possible. These will be the questions you will be quizzed on. Your notes and quiz score determine the credit you earn.

22. The Milky Way Galaxy is • Write the above question on your paper. • Choose the best answer but do not write down yet. • a. an irregular galaxy. • b. an elliptical galaxy. • c. a spiral galaxy. • d. a barred spiral galaxy.

23. The Milky Way Galaxy is • Now write the correct answer with the question. You should have written “The Milky Way is a spiral galaxy”. • a. an irregular galaxy. • b. an elliptical galaxy. • c. a spiral galaxy. • d. a barred spiral galaxy.

24. The stars in the Milky • Way galaxy are arranged • in the shape of • a. a sphere • b. an irregular cloud • c. a disc • d. a ring.

25. The stars in the Milky • Way galaxy are arranged • in the shape of • a. a sphere • b. an irregular cloud • c. a disc • d. a ring.

26. 3. A star observed at the opposite end of the Milky Way is seen as it appeared • at the moment of the Big • bang. • b. a few light years ago. • c. about 100,000 years ago. • d. about 8 minutes ago.

27. 3. A star observed at the opposite end of the Milky Way is seen as it appeared • at the moment of the Big • bang. • b. a few light years ago. • c. about 100,000 years ago. • d. about 8 minutes ago.

28. Our solar system is • located • near the center of our • galaxy. • b. in the galactic halo. • c. near the outer edge of the • our galaxy. • d. in the Andromeda galaxy.

29. Our solar system is • located • near the center of our • galaxy. • b. in the galactic halo. • c. near the outer edge of • our galaxy. • d. in the Andromeda galaxy.

30. 5. The Milky Way galaxy is billions of times more massive than the sun because

31. a. stars in the galaxy create matter from energy. b. gravitational lensing magnifies the mass of the galaxy.

32. c. the galaxy is denser than the sun. d. the galaxy contains billions of stars.

33. c. the galaxy is denser than the sun. d. the galaxy contains billions of stars.

34. Billions and Billions When astronomers built the first large telescopes they discovered many fuzzy patches of light in deep space.

35. Billions and Billions When astronomers built the first large telescopes they discovered many fuzzy patches of light in deep space.

37. Modern telescopes showed these fuzzy patches to actually be collections of billions of stars, galaxies. In fact, the most common object in the visible universe are galaxies.

38. Modern telescopes showed these fuzzy patches to actually be collections of billions of stars, galaxies. In fact, the most commonobject in the visible universe are galaxies.

40. There are hundreds of billions of galaxies, of various shapes and sizes, each containing hundreds of billions of stars and the nebulae they formed from.

41. There are hundreds of billions of galaxies, of various shapes and sizes, each containing hundreds of billions of stars and the nebulae they formed from.

43. 6. The numerous fuzzy patches that can be seen through telescopes in deep space are a. comets. b. asteroids. c. galaxies. d. planets.

44. 6. The numerous fuzzy patches that can be seen through telescopes in deep space are a. comets. b. asteroids. c. galaxies. d. planets.

45. You should have the following written on your paper: The numerous fuzzy patches that can be seen through telescopes in deep space are galaxies.

46. 7. The most common objects visible in deep space are a. comets. b. nebula. c. galaxies. d. asteroids.

47. 7. The most common objects visible in deep space are a. comets. b. nebula. c. galaxies. d. asteroids.

48. The light in galaxies • comes from • a. galactic collisions. • b. molecular clouds. • c. dust and gas. • d. billions of stars.

49. The light in galaxies • comes from • a. galactic collisions. • b. molecular clouds. • c. dust and gas. • d. billions of stars.

50. Most of the visible matter • in the universe consists of • clouds of hydrogen and • helium gas. • b. stellar remnants. • c. high energy radiation from • black holes. • d. stars in galaxies.