The passage states that Charon never sets because of:

A. an eclipse frenzy.
B. stellar occultations.
C. tidal coupling.
D. escaping methane.



The passage asserts that Charon's relationship with Pluto is unique in our solar system in regard to:

F. frequency of eclipses.
G. mutual tidal coupling.
H. synchronous rotation.
J. axial tilt.



The main point of the first paragraph is that:

A. Charon is more similar to Earth's moon than you might expect.
B. Charon is surprisingly similar to Pluto.
C. Charon's closeness to Pluto makes it appear huge from the surface of its planet.
D. in terms of size, the Earth is to Pluto as a billiard ball is to a pea.



As it is defined in the passage, the Sun's corona is:

  I. the Sun's outer atmosphere.
  II. illuminated by reflected light.
  III. reflected light.

F. I only
G. III only
H. I and III only
J. I, II, and III



The long spans of time that elapse between periods of eclipse frenzy on Pluto are the result of:

  I. Pluto's axial tilt.
  II. methane escaping Charon's surface.
  III. Charon's position relative to Pluto's equator.

A. I only
B. III only
C. I and II only
D. I and III only


The passage asserts that one feature of Pluto that is lacking on Charon is:

F. escaping methane.
G. noticeable gravity.
H. a cratered landscape.
J. methane frost.



It can reasonably be deduced from the first paragraph that the number of degrees in the Earth's sky taken up by our Moon is roughly:

A. 0.5 degree.
B. 1.0 degree.
C. 4.0 degrees.
D. 8.0 degrees.



The passage states that the methane ice on Charon evaporated because of that moon's:

  I. smaller mass.
  II. weaker gravity.
  III. axial tilt.

F. II only
G. I and II only
H. I and III only
J. I, II, and III



The passage states that all major satellites in our solar system have in common the fact that they have:

A. axial tilt and somewhat noticeable mutual tidal coupling.
B. closer proximity to their respective planets than our Moon has to Earth.
C. synchronous rotation caused by tidal coupling to their planets.
D. periods of eclipse that are frenzied and also serendipitous.



The passage suggests that the discovery of Charon was made even more interesting for scientists because that discovery coincided with:

F. the discovery of the synchronous rotation of satellites.
G. a large number of eclipses occurring on Pluto.
H. the realization that our Moon is identical to Charon.
J. a demonstration of tidal coupling by Earth and its Moon.