20121215

Astronomy quiz question: IAU classification scheme

Astronomy 210 Quiz 7, fall semester 2012
Cuesta College, San Luis Obispo, CA

Refer below to the minimal qualifications established by the International Astronomical Union for a planet:
I. Orbits the sun.
II. Shape "rounded-out" by gravity.
III. Cleared/dominates orbit around sun.
Of the following choices, which solar system object(s) only satisfies qualification I, but does not satisfy qualifications II and III?
(A) Mars' moon, Phobos, a captured asteroid.
(B) Makemake, a dwarf planet.
(C) Earth's moon.
(D) Mercury.
(E) (More than one of the above choices.)
(F) (None of the above choices.)

Correct answer: (F)

Phobos and Earth's moon both do not directly orbit the sun (qualification I). Makemake and Mercury both directly orbit the sun (qualification I), but are both rounded in shape (qualification II), while Mercury also dominates its orbit around the sun (qualification III). Thus none of these choices satisfies Both Almatheta and Earth's moon do not meet qualification I, but does not satisfy qualifications II and III.

Section 70158
Exam code: quiz07sEcn
(A) : 17 students
(B) : 6 students
(C) : 3 students
(D) : 1 student
(E) : 2 students
(F) : 5 students

Success level: 22% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.33

Section 70160
Exam code: quiz07n0iC
(A) : 10 students
(B) : 4 students
(C) : 2 students
(D) : 1 student
(E) : 0 students
(F) : 8 students

Success level: 36% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.67

No comments: