Astronomy current events question: Moon impact history

Astronomy 210L, spring 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!)

Karen Jenvey, Stacy Bowles, and Maria Martinez, "NASA Lunar Scientists Shed Light on Moon's Impact History," February 27, 2012
http://www.nasa.gov/centers/ames/news/releases/2012/12-19AR.html

Analysis of __________ by NASA researchers support the theory that the moon was impacted by a recent wave of high speed impacts 4 billion years ago.
(A) faint earthshine reflected by the moon.
(B) infrared images of still-molten lunar craters.
(C) different crater sizes and densities.
(D) smooth lunar lava flows.
(E) Antarctic meteorites.

Correct answer: (C)

Student responses
Sections 30678, 30679, 30680
(A) : 5 students
(B) : 4 students
(C) : 12 students
(D) : 2 students
(E) : 1 student