Cuesta College, San Luis Obispo, CA
An astronomy question on an online discussion board was asked and answered[*]:
Pdg: Can be Mars and Mercury be both low in the west at sunrise?Discuss how this answer is correct, and how you know this. Support your answer using a diagram showing the positions of the sun, Mars, Mercury, Earth, and an observer on Earth.
CON: No. Mars can be low in the west at sunrise, but Mercury cannot.
[*] answers.yahoo.com/question/index?qid=20170106000722AAkerYG.
Solution and grading rubric:
- p:
Complete diagram and reasoning includes the following explanations for an observer on Earth at sunrise (6 AM):- Mars can be placed in an orbit around the sun outside of Earth's orbit such that it is visible low over the observer's west horizon; and
- Mercury can be placed in an orbit around the sun inside of Earth's orbit but will never be visible low over the observer's west horizon.
- r:
Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. - t:
Problems with either diagram or discussion. May have:- Mars in an inner orbit and/or Mercury in an outer orbit; or
- observer not placed at sunset and/or east/west horizons switched.
- v:
Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Diagram and discussion problematic. - x:
Implementation/application of ideas, but credit given for effort rather than merit. - y:
Irrelevant discussion/effectively blank. - z:
Blank.
Section 30674
Exam code: midterm01nghT
p: 14 students
r: 0 students
t: 6 students
v: 0 student
x: 2 students
y: 0 students
z: 1 student
A sample "p" response (from student 9433):
