Astronomy current events question: seasons on Triton

Astronomy 210L, Spring Semester 2010
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Astronomy.com editors, "Triton's Summer Sky of Methane and Carbon Monoxide," April 7, 2010
http://www.astronomy.com/asy/default.aspx?c=a&id=9731

What is the evidence from the European Southern Observatory's Very Large Telescope that the atmosphere of Neptune's largest moon, Triton, changes with the seasons?
(A) Increasing amounts of gases.
(B) Shrinking polar caps.
(C) Changes in surface roughness.
(D) Shifting tectonic plates.
(E) Rising methane ocean levels.

Correct answer: (A)

Student responses
Sections 30678, 30679, 30680
(A) : 41 students
(B) : 2 students
(C) : 3 students
(D) : 3 students
(E) : 1 student