Astronomy midterm question: Venus-Jupiter transit

Astronomy 210 Midterm 1, Spring Semester 2011
Cuesta College, San Luis Obispo, CA

[20 points.] Consider an online definition of a type of an eclipse called a transit:

A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body... In rare cases, one planet can transit in front of another.
--http://en.wikipedia.org/wiki/Astronomical_transit

The next planetary transit will occur on November 22, 2065, when Venus transits (passes in front of) Jupiter. Show how this event would be possible, using a diagram showing the positions of the sun, Venus, Jupiter, Earth, and an observer on Earth.

Solution and grading rubric:

• p = 20/20:
  Correct. Correct and complete diagram, with Venus (inner heliocentric orbit) and Jupiter (outer heliocentric orbit) along line of sight of observer on Earth.
  
• 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. No actual transit in a plausible diagram where Venus (inner heliocentric orbit) and Jupiter (outer heliocentric orbit) are in opposition/conjunction with respect to each other, while Earth may or may not be between Venus and Jupiter. Or draws a transit in a problematic diagram, with both Venus and Jupiter in inner heliocentric orbits, or both in outer heliocentric orbits, where all three planets are in line with the sun.
  
• v = 8/20:
  Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Draws a transit, but in a geocentric model.
  
• x = 4/20:
  Implementation/application of ideas, but credit given for effort rather than merit. No transit, problematic model.
  
• y = 2/20:
  Irrelevant discussion/effectively blank.
  
• z = 0/20:
  Blank.
  

Grading distribution:
Section 30674
Exam code: midterm01n0M3
p: 9 students
r: 1 student
t: 20 students
v: 2 students
x: 7 students
y: 2 students
z: 0 students

A sample "p" response (from student 1450):

A sample "t" response (from student 7624), with Venus orbiting the sun outside Earth's orbit in order to transit Jupiter:

Another sample "t" response (from student 2336), with correct orbits, but no transit as seen from Earth:

A sample "v" response (from student 5259), with Jupiter orbiting Earth closer than Venus in a geocentric model: