1. Charles Hakes Fort Lewis College1

2. Charles Hakes Fort Lewis College2 Exploring the Heavens Lunar Phases Eclipses History

3. Charles Hakes Fort Lewis College3 Outline l Notes l Review l Lunar Phases; Eclipses (0.3) l History (1.1,1.2)

4. Charles Hakes Fort Lewis College4 Lab Notes No in-class lab this week. Telescope intro or resources part Be thinking about those “report” labs.

5. Charles Hakes Fort Lewis College5 Your Folder Full name on the tab BIG name on the front Major on upper right Class on lower left A comment about yourself on the lower right Inside - your most recent, or current, math class (subject, course number, and year taken.) Include your daily three minute papers! You can reuse pages, just add the date. Say something specific.

6. Charles Hakes Fort Lewis College6 Review What was the most important thing you learned? The smaller the parallax shift of an object the further away the object is. There are 2  radians in a circle.

7. Charles Hakes Fort Lewis College7 Radians Not just an extra button on your calculator 2  radians in a circle Conversion formula 2  rad = 360° Conversion practice page on-line!

8. Charles Hakes Fort Lewis College8 Small Angle Approximation Angle must be in radians Angle must be small (opposite << adjacent) Then:   sin(  )  tan(  )

9. Charles Hakes Fort Lewis College9 Small Angle Approximation For small angles in radians: angle = baseline/distance

10. Charles Hakes Fort Lewis College10 Small Angle Approximation For small angles in radians: angle = baseline/distance or distance = baseline/angle or baseline = angle*distance

11. Charles Hakes Fort Lewis College11 You see your friend in the distance and measure that they “subtend” 1 degree. How many radians is that? A) 57 B) 1.6 C).034 D).017 E).012

12. Charles Hakes Fort Lewis College12 You know your friend is 1.6m tall, and that they “subtend” 0.017 radians. How many far away are they? A) 94m B) 0.27m C) 163m D) 57m E) 106m

13. Charles Hakes Fort Lewis College13 Lunar Phases

14. Charles Hakes Fort Lewis College14 Figure 1.1 Lunar Phases

15. Charles Hakes Fort Lewis College15 Which lunar phase rises at Sunset? A) New. B) First quarter. C) Full. D) Third quarter.

16. Charles Hakes Fort Lewis College16 Which lunar phase rises at Sunset? A) New. B) First quarter. C) Full. D) Third quarter.

17. Charles Hakes Fort Lewis College17 Vocabulary phases new moon first quarter full moon third quarter crescent moon gibbous waxing waning

18. Charles Hakes Fort Lewis College18 Which lunar phase is overhead at sunset? A) New. B) First quarter. C) Full. D) Third quarter.

19. Charles Hakes Fort Lewis College19 Which lunar phase is overhead at sunset? A) New. B) First quarter. C) Full. D) Third quarter.

20. Charles Hakes Fort Lewis College20 Figure 1.1 Lunar Phases

21. Charles Hakes Fort Lewis College21 Eclipses

22. Charles Hakes Fort Lewis College22 Earth-Moon model

23. Charles Hakes Fort Lewis College23 Figure 1.2 Lunar Eclipse

24. Charles Hakes Fort Lewis College24 Figure 1.3 Solar Eclipse

25. Charles Hakes Fort Lewis College25 Figure 1.4 Solar Eclipse Types

26. Charles Hakes Fort Lewis College26 Figure 1.5 Eclipse Geometry

27. Charles Hakes Fort Lewis College27 Figure 1.6 Eclipse Tracks

28. Charles Hakes Fort Lewis College28 Discovery 1-1b The Scientific Method

29. Charles Hakes Fort Lewis College29 Review The tilt of the ecliptic is 23.5°. The tilt of the Moon’s orbit compared to the ecliptic is 5.2° The tilt is always 5.2°, however, the orbit precesses (wobbles). Cycle is ~18.6 years.

30. Charles Hakes Fort Lewis College30 Where does the full moon rise on June 21? A) North of east (by more than 5°) B) Within 5.2° of due east C) South of east (by more than 5°) D) Not enough information

31. Charles Hakes Fort Lewis College31 Where does the full moon rise on June 21? A) North of east (by more than 5°) B) Within 5.2° of due east C) South of east (by more than 5°) D) Not enough information

32. Charles Hakes Fort Lewis College32 Discussion Does the full moon get higher in the sky during summer or winter? The tilt of the Moon’s orbit compared to the ecliptic is 5.2° How high in the sky does the moon ever get? Where on the horizon would it rise then?

33. Charles Hakes Fort Lewis College33 Chapter 1 Planets

34. Charles Hakes Fort Lewis College34 Planets There are five “wanderers” in the sky. Two are morning/evening stars Mercury Morning or evening star. Always close to the sun Very quickly in and out of sight. Venus Morning or evening star. Brightest object next to the Sun and the Moon. Can see it in broad daylight.

35. Charles Hakes Fort Lewis College35 Planets Three are seen any time of night. Brightest during retrograde (westward) motion Mars Very red Seen about every two years Jupiter Brightest object next to Venus Seen about every year(+) Saturn Brighter than most stars Seen about every year(+)

36. Charles Hakes Fort Lewis College36 Figure 1.7 Planetary Motions

37. Charles Hakes Fort Lewis College37 Geocentric Universe Must explain both motion and brightness. Epicycles used to explain motion and brightness. Deferent is the larger circle on which the epicycle moves. Ptolomy (~A.D. 140) constructed the best of the geocentric models. Eventually had to add epicycles onto the epicycles.

38. Charles Hakes Fort Lewis College38 Figure 1.8 Geocentric Model

39. Charles Hakes Fort Lewis College39 Figure 1.9 Ptolemy ’ s Model

40. Charles Hakes Fort Lewis College40 Figure 1.10 Nicholas Copernicus (1473-1543)

41. Charles Hakes Fort Lewis College41 Helioentric Universe Sun centered model. The Copernican Revolution. Much simpler (recall Occam’s razor). But no more accurate. Epicycles still needed to explain all motion. Retrograde motion is just from perspective.

42. Charles Hakes Fort Lewis College42 Figure 1.11 Retrograde Motion

43. Charles Hakes Fort Lewis College43 Figure 1.12 Galileo Galilei (1564-1642)

44. Charles Hakes Fort Lewis College44 Galileo’s Observations First to use a telescope to look at objects in the sky. Moon mountains, craters. Sunspots. Jupiter’s moons. Venus phases. Supported the view that the Earth was not the center of things.

45. Charles Hakes Fort Lewis College45 Figure 1.13 Galilean Moons

46. Charles Hakes Fort Lewis College46 Figure 1.14a Venus Phases

47. Charles Hakes Fort Lewis College47 Figure 1.14b Venus Phases

48. Charles Hakes Fort Lewis College48 Summary Simpler models are better. The Earth is not the center of things.

49. Charles Hakes Fort Lewis College49 Review What was the most important thing you learned? The further north you go, the lower the sun gets. The opposite is true for the north star. The sun is always higher in Durango than GJ (Grand Junction) at noon. It’s a lot easier to find out the answer the (PRS) questions when you discuss it thoroughly with your classmates.

50. Charles Hakes Fort Lewis College50 Review What questions do you still have about today? If you did the Durango/Grand Junction thing in the tropics, would the results vary? Yes, because the sun could be either North or South of your position.

51. Charles Hakes Fort Lewis College51 How high does the sun ever get in the Durango (37° N latitude) sky? A) 37° above the Southern horizon B) 53° above the Southern horizon C) 76.5° above the Southern horizon D) 90° straight up

52. Charles Hakes Fort Lewis College52 How high does the sun ever get in the Durango (37° N latitude) sky? A) 37° above the Southern horizon B) 53° above the Southern horizon C) 76.5° above the Southern horizon D) 90° straight up

53. Charles Hakes Fort Lewis College53 Figure P.11 Parallax

54. Charles Hakes Fort Lewis College54 Distances to Stars The biggest baseline is the best. Use the diameter of the Earth’s orbit. (distance = baseline/angle) A Parsec is the distance of an object when the observed parallax shift is one arc second when the baseline is one average radius of the Earth’s orbit (1 Astronomical Unit = 1 AU). 1 pc = 3.09x10 13 km = 3.3ly

55. Charles Hakes Fort Lewis College55 Figure 10.1 Stellar Parallax

56. Charles Hakes Fort Lewis College56 You observe identical twins in the distance and measure their angular height. Joe appears 0.8 degrees tall and Bob appears 0.3 degrees tall. A) Joe is a little farther away than Bob B) Joe is more than twice as far away as Bob C) Bob is a little farther away than Joe D) Bob is more than twice as far away as Joe E) Not enough information

57. Charles Hakes Fort Lewis College57 You observe identical twins in the distance and measure their angular height. Joe appears 0.8 degrees tall and Bob appears 0.3 degrees tall. A) Joe is a little farther away than Bob B) Joe is more than twice as far away as Bob C) Bob is a little farther away than Joe D) Bob is more than twice as far away as Joe E) Not enough information

58. Charles Hakes Fort Lewis College58 Three Minute Paper Write 1-3 sentences. What was the most important thing you learned today? What questions do you still have about today’s topics?