Astronomy current events question: gas-powered comet jets

Astronomy 210L, Fall Semester 2010
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!)

Astronomy.com editors, "Primordial Dry Ice Fuels Comet Jets," November 11, 2010
http://astronomy.com/en/News-Observing/News/2010/11/Cometary%20dry%20ice%20jet%20fuel.aspx

The NASA EPOXI spacecraft observed jets of gas and particles powered by __________ bursting from Comet 103P/Hartley 2.
(A) oxygen.
(B) water vapor.
(C) nitrogen.
(D) carbon dioxide.
(E) methane.

Correct answer: (D)

Student responses
Sections 70178, 70186, 70200
(A) : 0 students
(B) : 9 students
(C) : 10 students
(D) : 43 students
(E) : 2 students