Astronomy current events question: dating impact craters on the moon

Astronomy 210L, spring semester 2019
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!)

News release, "Team of Scientists led by U of T Identify Period of Increased Asteroid Impacts on Ancient Earth by Studying the Moon" (January 17, 2019)
utoronto.ca/news/team-scientists-led-u-t-identify-period-increased-asteroid-impacts-ancient-earth-studying-moon

Analysis of __________ observed by NASA's Lunar Reconnaissance Orbiter spacecraft indicate asteroid impacts on the moon and Earth have increased 290 million years ago.
(A) magnetic field fluctuations.  
(B) subsurface ice.  
(C) moonquakes.
(D) heat radiated from rocks.
(E) existing asteroid orbits.

Correct answer: (D)

Student responses
Sections 30679, 30680
(A) : 12 students
(B) : 3 students
(C) : 2 students
(D) : 17 students
(E) : 10 students