## 20110116

### Astronomy final exam question: Mars closer to sun?

Astronomy 210 Final Exam, Fall Semester 2010
Cuesta College, San Luis Obispo, CA

[20 points.] Suppose Mars had instead formed closer to the sun, in Venus' orbit. Explain the expected characteristics of this closer-to-the-sun Mars, in terms of its internal heat and geological activity, compared to Mars today in its current orbit.

• p = 20/20:
Correct. Extent of internal heat and geological activity of a terrestrial planet depends on its mass, thus Mars would essentially have the same amount of internal heat and geological activity at any distance from the sun.
• 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. At least recognizes that internal heat and geological activity is correlated with mass.
• v = 8/20:
Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Discussion based closer proximity to the sun creating more greenhouse effect and/or more geological activity.
• x = 4/20:
Implementation/application of ideas, but credit given for effort rather than merit. Decides on same/different relative amount of internal heat and geological activity without supporting statements.
• y = 2/20:
Irrelevant discussion/effectively blank.
• z = 0/20:
Blank.
Section 70158
p: 4 students
r: 3 students
t: 2 students
v: 29 students
x: 3 students
y: 0 students
z: 1 student

A sample "p" response (from student 1122):

A sample "v" response (from student 4321), discussing how more heat from the sun would cause more volcanic activity:

Another sample "v" response (from student 1986), again discussing how more heat from the sun would cause more volcanic activity: