1. Astronomy 1010-H Planetary Astronomy Fall_2015 Day-9

3. Course Announcements Read Chapter 2 How is the lunar observing going? How is the sunset/sunrise observing going? 1 st Quarter night – Mon. 9/21 -7:30pm – on campus Exam 1: Fri. Sept. 18 or Mon. Sept. 21 This Week: APSU-OUR: Research & Creative Activity Week. Events in the library 2:30-3:30 every day.APSU-OUR

4. Spacecraft Reports Chantal H. – New Horizons Ashley G. – Dawn Mahalia S. – NuStar Tristan C. – Mangalyaan Spencer B. – Voyager Arielle P. – Curiosity Rover Lars A. – Cassini Sarah E. – Rosetta John M. – Mars Phoenix Jordan T. – Galileo Rashun B. – Apollo Missions

5. Definitions & Terms -1 Season: A time

6. Stuff in Chapter 2 Coordinates Position Daily Motion (spin of Earth on its axis) Visibility of the sky Year Motion (Earth orbits the Sun) Seasons (tilt of the Earth’s axis) Precession of the equinoxes Motion and phases of the Moon Eclipses

7. Earth’s Axis  Earth’s axis is not perpendicular to the ecliptic plane.  Instead, it is at an angle of 23.5 degrees.  This is why there are seasons.

8. Earth’s Axis  The angle of sunlight is closer to perpendicular in summer.  Energy is more concentrated.  The southern hemisphere is opposite the northern hemisphere.

9. Special Days of the Year  Summer solstice: Sun farthest north.  Autumnal equinox: Sun on the equator, moving southward.  Winter solstice: Sun farthest south.  Vernal equinox: Sun on the equator, moving northward.

10. Lecture – Tutorial Path of the Sun: pg 89 Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with each other. Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another group. If you get really stuck or don’t understand what the Lecture Tutorial is asking, ask one of us for help.

11. I Realize this is Like Trying to Drink from a Fire Hose

12. Lecture – Tutorial Seasons: pg. 93 Work with a partner! Yada Yada Yada … This one is homework

13. Stuff in Chapter 2 Coordinates Position Daily Motion (spin of Earth on its axis) Visibility of the sky Year Motion (Earth orbits the Sun) Seasons (tilt of the Earth’s axis) Precession of the equinoxes Motion and phases of the Moon Eclipses

14. Precession  Currently, the north celestial pole is near the bright star Polaris.  Earth’s axis wobbles with a period of 26,000 years.  Location of the poles slowly shifts.

15.  Earth wobbles like a top, slowly.  Since the axis shifts, the equator shifts.  Positions of the equinoxes precess as well.

16. Stuff in Chapter 2 Coordinates Position Daily Motion (spin of Earth on its axis) Visibility of the sky Year Motion (Earth orbits the Sun) Seasons (tilt of the Earth’s axis) Precession of the equinoxes Motion and phases of the Moon Eclipses

17. The Moon’s Motions Because the orbit is elliptical and not circular, the rotation speed doesn’t always match the orbital speed.

18. The Month? Full Moon to Full Moon takes 29.53 days

20. The Cycle of Lunar Phases

21. The moon does rotate. The moon takes the same amount of time to complete one rotation as it does to complete one orbit

22. The orbital period is not the same as the cycle of phases Cycle of phases: The synodic month 29.53 days The Orbital Period is the Sidereal Month: 27.32 days

23. Lecture – Tutorial Cause of Moon Phases: pg 81 Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with one another. Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another group. If you get really stuck or don’t understand what the Lecture Tutorial is asking, ask one of us for help.

24. Lecture – Tutorial Predicting Moon Phases: pg 85 Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with one another. Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another group. If you get really stuck or don’t understand what the Lecture Tutorial is asking, ask one of us for help.

25. Course Announcements Smartworks Chapter 2: Fri. 9/19 Read Chapter 2, 3 Dark Night Observing – Tues. 9/16 & Wed. 9/24 – 7:30pm at the Observatory Exam-1 – Friday Sept. 19 Bring L-T book to the Exam on Friday

26. Lecture – Tutorial Predicting Moon Phases: pg 85 Work with a partner! Read the instructions and questions carefully. Discuss the concepts and your answers with one another. Come to a consensus answer you both agree on. If you get stuck or are not sure of your answer, ask another group. If you get really stuck or don’t understand what the Lecture Tutorial is asking, ask one of us for help.

27. Stuff in Chapter 2 Coordinates Position Daily Motion (spin of Earth on its axis) Visibility of the sky Year Motion (Earth orbits the Sun) Seasons (tilt of the Earth’s axis) Precession of the equinoxes Motion and phases of the Moon Eclipses

28. Eclipses!

29.  Three types of solar eclipses: Total: The Moon completely blocks the Sun’s light. Partial: Only part is blocked. Annular: The Sun appears as a bright ring surrounding the Moon.

30. Solar Eclipses  Solar eclipses happen at new Moon.  Moon passes between Earth and the Sun.  Only a small portion of Earth can witness each one.

31.  The part of the Moon’s shadow you are in determines which type of solar eclipse you see.  Umbra: Total or annular.  Penumbra: Partial.

32.  Lunar eclipses happen at full Moon.  Earth is between the Sun and the Moon.  Visible over a wider area of Earth.  Last a lot longer than solar eclipses.

33.  Eclipses do not occur every month because the Moon’s orbit is tilted 5.2° with respect to Earth’s orbit around the Sun.  Intersection: line of nodes.

34. Lunar Eclipse: Earth passes directly between the Sun & Moon

35. The Total Lunar Eclipse Next one is April 15, 2014 for North America

36. A Solar Eclipse requires much more precise alignment

37. The Moon’s shadow is not large enough to cover the Earth

38. Partial eclipses are more common than total eclipses

39. Annular Eclipses occur when the Moon is at or near apogee

40. Solar Eclipses take hours to develop but last only minutes

41. During a total eclipse the Sun’s corona is visible

42. Predicting Eclipses The Saros Cycle…18 years 11.3 days

43. What Would You See on Mars?

44. Exam-1 to here

45. Projected Eclipse Times Eclipse Path Point of Greatest Eclipse Lat.: 36.9664° N Long.: 87.6639° W Total Solar Eclipse Duration of Totality: 2m40.1s APSU Observatory Lat.: 36.5631° N Long.: 87.3433° W Total Solar Eclipse Duration of Totality: 2m23.4s

46. Projected Eclipse Times APSU Observatory Lat.: 36.5631° N Long.: 87.3433° W Total Solar Eclipse Duration of Totality: 2m23.4s Magnitude: 1.008 Event Date Time (UT) Alt Azi (C1) : 2017/08/2116:56:59.80 62.3° 149.7° (C2) : 2017/08/2118:25:28.70 64.2° 198.9° Max : 2017/08/2118:26:40.50 64.1° 199.5° (C3) : 2017/08/2118:27:52.10 64° 200.2° (C4) : 2017/08/2119:52:25.50 53.4° 235.2°

47. Projected Eclipse Weather

48. Clarksville, TN

49. Two-Minute Essay  My name is…  The scientist (living or dead, but real) I would most like to meet is: