Astronomy current events question: Mars' water-related crater features

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!)

Francesco Salese, Gian Gabriele Ori, Dmitri Titov, and Markus Bauer, "First Evidence of Planet-Wide Groundwater System on Mars" (February 28, 2019)
esa.int/Our_Activities/Space_Science/Mars_Express/First_evidence_of_planet-wide_groundwater_system_on_Mars

Images of __________ sent back by the European Space Agency's Mars Express spacecraft support predictions of underground water on ancient Mars.
(A) sinkholes.
(B) glacier tracks.
(C) crater wall features.
(D) inactive steam vents.
(E) collapsed lava tubes.

Correct answer: (C)

Student responses
Sections 30679, 30680
(A) : 1 student
(B) : 11 students
(C) : 22 students
(D) : 5 students
(E) : 0 students