Astronomy current events question: Comet 67P/Churyumov–Gerasimenko's water-ice cycles

Astronomy 210L, fall semester 2015
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!)

Maria Cristina De Sanctis, Fabrizio Capaccioni, Matt Taylor, Markus Bauer, "Rosetta Reveals Comet's Water-Ice Cycle" (September 23, 2015)
esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_reveals_comet_s_water-ice_cycle

The European Space Agency's Rosetta spacecraft identified __________ on Comet 67P/Churyumov–Gerasimenko that varies with its rotation.
(A) radioactivity.
(B) micro-avalanches.
(C) steam geysers.
(D) water-ice.
(E) comet-quakes.

Correct answer: (D)

Student responses
Sections 70178, 70186
(A) : 5 students
(B) : 1 student
(C) : 4 students
(D) : 23 students
(E) : 1 student