Cuesta College, San Luis Obispo, CA
The image at right[*] posted on the Instagram account of the U.S. Department of the Interior depicts a moon low above a horizon during the day. Discuss whether or not this moon image is plausible, and how you know this. Support your answer using a diagram showing the positions of the sun, the moon, Earth, and an observer on Earth.
Solution and grading rubric:
Correct. The waning gibbous moon (more than the left half of the moon is lit up) is highest overhead at 3:00 AM, and would have risen six hours before at 9:00 PM, and set six hours later at 9:00 AM. In order for this picture to have been taken during the day, the time would need to sometime between after sunrise at 6:00 AM, and when the waning gibbous moon would set at 9:00 AM. Complete diagram and reasoning.
Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Diagram and/or explanation has minor errors.
Contains right ideas, but discussion is unclear/incomplete or contains major errors. Problems with either diagram or discussion.
Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Diagram and discussion problematic.
Implementation/application of ideas, but credit given for effort rather than merit.
Irrelevant discussion/effectively blank.
Exam code: midterm01sh3P
p: 28 students
r: 8 student
t: 9 students
v: 3 students
x: 4 students
y: 0 students
z: 0 students
A sample "p" response (from student 3562):