## 20111012

### Astronomy midterm question: full moon at noon?

Astronomy 210 Midterm 1, fall semester 2011
Cuesta College, San Luis Obispo, CA

[20 points.] An astronomy question on an online discussion board(*) was asked and answered:
wakeflaw...: It's noon and the [m]oon is full. Where is the moon in the sky?
Renaissance...: On the opposite side of the world.
Discuss whether or not this answer is correct, and how you know this. Support your answer using a diagram showing the positions of the sun, moon, Earth, and an observer on Earth.

• p = 20/20:
Correct. The full moon is highest overhead for an observer at midnight on Earth, which on the opposite side of Earth as the noon observer. Correct diagram and reasoning.
• r = 16/20:
Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
• t = 12/20:
Contains right ideas, but discussion is unclear/incomplete or contains major errors. Problems with either diagram or discussion.
• v = 8/20:
Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Substantive discussion, but missing/problematic diagram.
• x = 4/20:
Implementation/application of ideas, but credit given for effort rather than merit. Problematic discussion, diagrams with the moon orbiting the sun, etc.
• y = 2/20:
Irrelevant discussion/effectively blank.
• z = 0/20:
Blank.
Section 70158
Exam code: midterm01sg5U
p: 16 students
r: 7 students
t: 7 students
v: 4 students
x: 3 students
y: 0 students
z: 0 students

A sample "p" response (from student 1131):

Another sample "p" response (from student 9275):

A sample "t" response (from student 1863):

A sample "x" response (from student 2319):