Astronomy current events quiz question: Kirkwood blueberries on Mars

Astronomy 210L, fall semester 2012
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!)

Alan Boyle, "Spheres Spark New Martian Mystery," September 14, 2012
http://cosmiclog.nbcnews.com/_news/2012/09/14/13868790-spheres-spark-new-martian-mystery

The NASA Mars Science Laboratory Curiosity rover has discovered tightly packed blueberries that __________ than blueberries observed earlier by the Opportunity rover. (A) are softer and less iron-rich. (B) contain more water. (C) are larger and less blue. (D) are more radioactive. (E) contain more organic molecules.

Correct answer: (A)

Student responses
Sections 70178, 70186, 70200
(A) : 35 students
(B) : 1 student
(C) : 10 students
(D) : 2 students
(E) : 5 students