Agenda:

1. Agenda: LECTURE: • Formal Lab Report DUE on FOV & Collect both Tutorials • Briefly Magnitudes (apparent and absolute) • Seasons and Path of the Sun • Tutorial: Seasons • Build Solar Demonstrators if time permits. LAB: Celestial Sphere & Solar Motion Lab (maybe build Solar Demonstrators)

2. Week 6Seasons & Path of Sun

3. Where would the Sun be on your birthday?

4. Complete this statement! What time is it when the Sun is highest in the sky on a given day? _______________ At noon, is the Sun highest in the sky during summer, winter or the equinoxes? ______________ How about lowest in the sky? ______________

5. Which of these are true and which are false and what evidence is there to support your answer? • Earth is closer to the Sun in summer than it is in the winter. • When it is summer, the Sun is giving off more energy and when it is winter the Sun is giving off less energy. • When it is summer, more sunlight reaches Earth than it does during the winter.

6. Seasons Animation • Note how the tilt of Earth’s rotational axis and Earth’s position in its orbit about the Sun affect how muchdirectsunlight shines on the northern and southern hemispheres. • How is this related to the seasons? http://bcs.whfreeman.com/universe6e/pages/bcs-main.asp?v=category&s=00110&n=02000&i=02110.03&o=|02000|01000|&ns=0

7. When the Sun is high in the sky during the day, the number of daylight hours is greater and the amount of direct sunlight received is greater. This results in Summer.

8. Where would the Sun be on your birthday?

9. When the Sun is low in the sky during the day, the number of daylight hours is less and the amount of direct sunlight received is less. This results in Winter.

10. The tilt of Earth’s axis of rotation produces longer (or shorter) hours of more (or less) direct sunlight

11. The tilt of Earth’s axis of rotation produces longer (or shorter) hours of more (or less) direct sunlight Which positions (1, 2, 3, or 4) correspond with which seasons (fall, summer, spring, winter) for the northern hemisphere? What about the southern hemisphere? 1 4 2 3

12. The tilt of Earth’s axis of rotation produces longer (or shorter) hours of more (or less) direct sunlight What are the possible dates for positions 1, 2, 3, and 4? 1 4 2 3

13. The tilt of Earth’s axis of rotation produces longer (or shorter) hours of more (or less) direct sunlight

14. Lecture Tutorial (pg 91-94): Seasons • 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 your Professor for help.

15. Sunlight Sunlight a c 2 3 b e Sun Note: this drawing is not to scale. In fact you could fit more than 11,000 Earths between the Sun and the Earth. d Looking at the images below, which letter (a-e) best represents winter in the United States?

16. Which of the locations identified with an “x” for each of the situations (A – E) would experience the coolest temperature over the course of one day? Cross-Tab Label 0 / 10

21. The changing position of the Sun during the year!

22. meridian X Zenith or overhead east south west How can we describe the motion of the sun in the sky?

23. How can we describe the motion of the sun in the sky? meridian zenith LUNCH!! PM or post meridian AM or ante meridian east south west

24. hereorthere? Where is the Sun at noon today? zenith east south west

25. Where is the Sun at noon today? zenith What about tomorrow at noon? there east south west

26. What about the path of the Sun? zenith What about tomorrow at noon? JUST A LITTLE HIGHER ! there east south west

27. June 21 Summer Solstice Mar 21 (Vernal) and Sept 21 (Autumnal) Equinox Dec 21 Winter Solstice Where is the Sun throughout the year? zenith east south west

28. The time for the sun to go from being highest in the sky at noon, to lowest and back to highest again is… ONE YEAR zenith east south west

29. Where would the Sun be on your birthday?

30. Position of the Sun when photographed during the day of the winter and summer solstice

31. If you were in the Southern Hemisphere, where would the Sun be when highest in the sky? • Northward • Southward • Eastward • Westward

32. If you are located in the continental U.S. on the first day of October, how will the position of the Sun at noon be different two weeks later? • It will have moved toward the north. • It will have moved to a position higher in the sky. • It will stay in the same position. • It will have moved to a position closer to the horizon. • It will have moved toward the west. 0/0