Astronomy Laboratory

Sunrises and Sunsets

 

 

 

Is this the little girl I carried?
Is this the little boy at play?
I don’t remember growing older,
When did they?

When did she get to be a beauty?
When did he grow to be so tall?
Wasn’t it yesterday when they were small?

Sunrise sunset, sunrise, sunset,
Swiftly flow the days,
Seedlings turn overnight to sunflowers,
Blossoming even as they gaze . . .

Sunrise sunset, sunrise, sunset!
Swiftly fly the years,
One season following another,
Laden with happiness and tears . . .

One season following another,
Laden with happiness and tears . .

 

from Fiddler on the Roof

 

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


I.  Sunrises

 

1.  Examine what you already know about sunrises.  Recall where you may have seen the Sun rise, what you’ve been taught, and think about what makes sense to you.  Now, make a hypothesis.  Where does the Sun rise?  Does it always rise in the same location?  Write your hypothesis below.  (It is strongly suggested you use a pencil for this activity.)

 

 

 

 

 

 

 

Now, you will be lead in to conducting a scientific examination.  The best way would be to observe the Sun rising yourself, but that’s not always feasible.  Therefore, observations you might make on your own are provided for you.

 

Examine the following table.  It shows the locations of sunrises throughout the year, taken on non-specific days in the season indicated.  Sunrise locations are by compass azimuth, where north is 0°, south is 180°, and so on.


 

Approximate time of year

Sunrise Location

Approximate time of year

Sunrise Location

a. Early Spring

91.4°

g. Early Autumn

91.6°

b. Mid Spring

84.8°

h. Mid Autumn

101.3°

c. Late Spring

74.8°

i. Late Autumn

113.7°

d. Early Summer

61.2°

j. Early Winter

120.7°

e. Mid Summer

72.5°

k. Mid Winter

110.5°

f. Late Summer

83.9°

l. Late Winter

101.7°

 

 

2.  To help visually organize this data, plot these points and label them on the horizon below.  Use a small sun symbol and place it right on the horizon line (the irregular line at the top of the diagram).

 

 

 

 

 

 

 

 

60°                               75°                               90°                               105°                             120°

NE                                                                   E                                                                     SE

 

 

3.  Reflect on your hypothesis.  Was it correct?  How did the observational data change your ideas about sunrises?  Revise your hypothesis if necessary and state it below.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.  From the table on the preceding page, what times of year does the Sun rise closest to due east?  Can you infer on what two exact days the Sun rises due east?  You may need to consult your textbook regarding seasons and associated specific dates.

 

 

 

 

 

 

 

 

 

 

 

5.  From the table, when does the Sun rise furthest north and furthest south?  On what exact days does this occur?

 

 

 

 

 

 

 

 

 

 

 

6.  Reflect on how seasons affect the length of daylight hours and when these occur.  Also, think about the reasons why sunrise location changes with the season.  What are the primary factors influencing seasons, the length of daylight, and the path the Sun takes across the sky?  Write down your ideas.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

II.  Sunsets

 

1.  Based on your reasoning in number 6, infer another hypothesis.  Write it below.  For each of the sunrise locations, where would the corresponding sunset occur?  Use the circle below to plot both sunrises and corresponding sunsets (label with lower-case letter).  Assume the circle is a full 360° horizon.  Use a protractor to be accurate.

 

 

 

 

 

 

 

 
 

 

 

 


 

180°

 
 

 

 

 

 


2.  Check your hypothesis at the following website:

 

 Sunrises and sunsets


 

If your hypothesis was incorrect, explain what the website provides that changes your thinking.  Correct the above diagram if necessary. 

 

3.  Does part II influence your understanding of why the amount of daylight changes seasonally?  If your thoughts from I.6 have changed, what do you know now?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.  Reflect on what you have learned from this laboratory.  Summarize your reflections in a few sentences.  In addition, consider how seasons and daylight would be different if the Earth had no tilt, or if the tilt was significantly more extreme.  Explain.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Additional web resource:  http://www-istp.gsfc.nasa.gov/stargaze/Ssky.htm