"The joy of life comes from our encounters with new experiences, and hence there is no greater joy than to have an endlessly changing horizon, for each day to have a new and different sun."
--Christopher Johnson "Alex" McCandless, letter to Ronald Franz (April 1992).
Equipment
Cuesta ThinkPad laptops (wireless networking, internet browser)
(appropriate, responsible in-class use of personal laptops allowed)
Current Events Quiz
(First 10 minutes of laboratory.)
Briefing
Cycles of the Sun (*.blog)
Big Idea
The sun has properties, locations, and predictable patterns of motion on the celestial sphere that can be observed and described. These celestial motions explain such phenomena as the day, the year, and the seasons.
Goal
Students will conduct a series of inquiries about the motion of the sun in the sky using prescribed internet simulations, and learn how the sun follows different pathways at different times of the year.
Computer Setup
Access the Heavens Above website, set for your campus, by clicking on the appropriate link below, and then select "Astronomy > Interactive Sky Chart":
*Bowen Observatory, San Luis Obispo campus (*.html)
*Telescope shelter, North County campus (*.html)
You should now see a star chart for the current time/date, where north is at the top, and west is to the right.
Tasks
(Record your lab partners' names on your worksheet.)
1. Exploration- On a map of the United States, north is toward the top of the page and west is to the left. On all of the star charts, north is toward the top of the page and west is to the right. How do you account for this difference?
Explanation: ___________.
- This is the current sky. Find the yellow dot marking the current location of the sun. Which constellation is it closest to right now? If you do not see the sun, it might be set to night-time; add or subtract enough hours until you do see it.
Closest constellation to the sun: _________.
- Change the time by increasing it one hour and pressing submit. Exactly how has the sun's position change on the map?
Description of change in position: ___________.
- Slowly increase the time to later and later in the day. This system probably uses 24- hr military time. So, 6:00 PM is actually entered as 1800 hours. Determine precisely the time (hours and minutes) that the sun will set tonight (expressed in either conventional or military time).
Sunset time: __________.
- Which constellation was the sun closest to when it set? Is this the same or different than where the sun was earlier in the day?
Closest constellation to the sun, while setting: __________.
Same or different? __________.
- What generalization can you make about the relative speeds that the sun and the stars move through the sky over the course of a day?
Generalization of sun and star speed(s): __________.
- What generalization can you make about the direction the sun and the stars move through the sky over the course of a day?
Generalization of sun and star direction(s) of movement: ___________.
Answer the following questions when looking at the star map set for sunset tonight.
- On what part of the map (left, right, top, bottom or center) is the constellation that appears highest overhead in the night sky? What is the name of this constellation?
Map position/name of constellation: __________, __________.
- On what part of the map (left, right, top, bottom or center) is the constellation that appears near the southern horizon? What is the name of this constellation?
Map position/name of constellation: __________, __________.
- On what part of the map (left, right, top, bottom or center) is the constellation that appears near the eastern horizon? What is the name of this constellation?
Map position/name of constellation: __________, __________.
Answer the following questions when looking at the star map set for three hours after sunset tonight.
- On what part of the map (left, right, top, bottom or center) is the constellation that now appears highest overhead in the night sky? What is the name of this constellation?
Map position/name of constellation: __________, __________.
- Where did the stars that used to be at this position (highest overhead) move?
Map position to where previous constellation moved: __________.
- On what part of the map (left, right, top, bottom or center) is the constellation that now appears near the southern horizon? What is the name of this constellation?
Map position/name of constellation: __________, __________.
- Where did the stars that used to be at this position (southern horizon) move?
Map position to where previous constellation moved: __________.
- On what part of the map (left, right, top, bottom or center) is the constellation that now appears near the western horizon, where the sun sets? What is the name of this constellation?
Map position/name of constellation: __________, __________.
- Where did the stars that used to be at this position (western horizon) move?
Map position to where previous constellation moved: __________.
- On what part of the map (left, right, top, bottom or center) is the constellation that now appears near the eastern horizon, where the sun rises? What is the name of this constellation?
Map position/name of constellation: __________, __________.
- Where did the stars that used to be at this position (eastern horizon) move?
Map position to where previous constellation moved: __________.
- If you were to change the time to midnight, predict what would be different about the positions of the stars.
Prediction of star positions at midnight: ___________.
- What generalization statement can you make about how the stars in different parts of the sky change position over the course of the night?
Generalization of star motion: __________.
2. Does Evidence Match a Given Conclusion?
Consider the research question, "How does the time of sunset change over the course of a year at this location?" Using the heavens-above.com "Astronomy > Sun" option for SLO campus (*.html) or NC campus (*.html), set for standard time only), determine precisely (hours and minutes) the sunset times for the following dates:
| Date: | Sunset time: |
| Tonight | ______ |
| One month from now | ______ |
| Two months from now | ______ |
| Three months from now | ______ |
| Six months from now | ______ |
| Nine months from now | ______ |
| Twelve months from now | ______ |
If a student proposed a generalization that, "Sunset time changes about one hour per month, setting earlier and earlier in the fall and then setting later and later in the spring," would you agree or disagree with the generalization based on the evidence you collected by analyzing the pattern of sunset times? Explain your reasoning and provide evidence either from the above questions or from evidence you yourself generate using the sky chart program(*).
3. What Conclusions Can You Draw From This Evidence?
A very broad observation is that the sun sets in the general direction of west. What conclusions and generalizations can you make from the following data collected by a student in terms of "How does the specific direction of where the sun sets change?"
| Date: | Sunset time: | Azimuth
(due west is 270°): | Direction: |
| August 15 | 7:00 PM | 289° | NW |
| September 15 | 6:10 PM | 274° | W |
| October 15 | 5:20 PM | 258° | WSW |
| November 15 | 4:40 PM | 245° | SW |
| December 15 | 4:30 PM | 238° | SSW |
(Evidence collected from "Astronomy > Sun," Heavens Above website for Laramie, WY (*.html).)
Explain your reasoning and provide specific evidence, with sketches if necessary, to support your reasoning(*).
4. What Evidence Do You Need to Pursue?
Describe precisely what evidence you would need to collect (using the Heavens Above website) in order to answer the research question, "How does the noon-time sun's position above the southern horizon change over the semester?" You do not need to actually complete the steps in the procedure you are writing.
Create a detailed, step-by-step description of evidence that needs to be collected and a complete explanation of how this could be done--not just "record the position of the sun," but exactly what would someone need to do, step-by-step, to accomplish this. You might include a table and sketches--the goal is to be precise and detailed enough that someone else could follow your procedure(*).
5. Formulate a Question, Pursue Evidence, and Justify Your Conclusion
Design an answerable research question (*.html), proposing a plan to pursue evidence using an aspect of the Heavens Above website that you have not completed before.
Research report summary on whiteboards(*), to be worked on and presented as a group, should include:- Specific research question.
Step-by-step procedure to collect evidence.
- Data table and/or results.
- Evidence-based conclusion statement.
Preparation/Reflection Points
1.0 = Pre-lab reading assignment
1.0 = Current events quiz
1.0 = Post-lab reflection assignment
Group Work Points(*)
Documentation (Tasks 1-4, graded from randomly selected group member)
2.0 = exploration complete and reasoning correct
1.5 = minor problem with exploration or reasoning
1.0 = minor problems with both exploration and reasoning
0.5 = problematic exploration and reasoning
2.0 = Poster/presentation (task 5)
(Graded for completion this week)
(Backwards Folded Scaffolding laboratory used with permission from: Tim Slater, Stephanie Slater, Daniel J. Lyons, Engaging in Astronomical Inquiry, W.H. Freeman & Company, New York (2010), pp. 13-22.)
Post-lab assignment 2 (*.html)
Due one hour before start of next lab
Go to next lab's weblink:
Preview online presentation
Complete online pre-lab assignment
Read current events study guide links for upcoming quiz
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