Which of the following statements about comets and asteroids is true?
A) Only asteroids collide with Earth.
B) Comets are frozen balls of ice and dust.
C) Most of the trillions of comets in our solar system have tails.
D) All asteroids lie in the asteroid belt between Mars and Jupiter.
E) There are about 1 million known asteroids in the solar system.
B) Comets are frozen balls of ice and dust.
How can primitive meteorites be distinguished from processed meteorites?
A) Radiometric dating shows that primitive meteorites are slightly older.
B) Radiometric dating shows that primitive meteorites are slightly younger.
C) Primitive meteorites always contain iron and processed meteorites do not.
D) Primitive meteorites always contain rocky material and processed meteorites do not.
E) Primitive meteorites always contain carbon compounds and processed meteorites do not.
A) Radiometric dating shows that primitive meteorites are slightly older.
Why aren’t small asteroids spherical in shape?
A) The force of gravity in small asteroids is less than the resistance of the rock to deform.
B) Small asteroids have odd shapes because they were all chipped off larger objects.
C) Large asteroids were once molten and therefore became spherical, but small asteroids were never
molten.
D) Large asteroids became spherical because many small collisions chipped off pieces until only a
sphere was left; this did not occur with small asteroids.
A) The force of gravity in small asteroids is less than the resistance of the rock to deform.
Where are the Trojan asteroids located?
A) in orbits around Jupiter
B) along Jupiter’s orbit, 60° ahead of and behind Jupiter
C) in the center of the asteroid belt
D) in orbits that cross Earth’s orbit
E) in orbits that cross Mars’s orbit
B) along Jupiter’s orbit, 60° ahead of and behind Jupiter
What surprising discovery did the New Horizons spacecraft make during its recent flyby of Pluto?
A) Pluto has the largest known volcano in the solar system.
B) Pluto’s surface consists mostly of rocky material.
C) Pluto’s surface shows signs of very recent geological activity.
D) Pluto really is a lost moon of Neptune.
E) None of the above
C) Pluto’s surface shows signs of very recent geological activity.
What causes the meteor showers we witness on Earth?
A) Earth passes through remnants of an impacted asteroid
B) Earth passes through the asteroid belt
C) Earth passes through the coma of a comet
D) Earth passes through comet dust particles
E) Earth passes through solar wind particles
D) Earth passes through comet dust particles
n what way does the figure on the right give a poor representation
of the asteroid belt?
A) For a correct scale, the asteroids should be drawn much smaller. This image gives the impression that the asteroid belt is very crowded.
B) The image does not show where most of the asteroids are
located in the solar system.
C) It shows the positions of the asteroids at a mix of times.
D) all of the above
A) For a correct scale, the asteroids should be drawn much smaller. This image gives the impression that the asteroid belt is very crowded.
What type of energy transport is occurring just below the photosphere of the Sun?
A) conduction
B) radiation
C) convection
D) emission
E) we do not know, since we cannot see below the photosphere
C) convection
How much mass does the Sun lose through nuclear fusion per second?
A) 4 tons
B) 4 million tons
C) 600 tons
D) 600 million tons
E) None; mass-energy is conserved so the sun cannot be losing mass.
B) 4 million tons
What observations characterize solar maximum?
A) The Sun becomes much brighter.
B) The Sun emits light of longer average wavelength.
C) The Sun rotates faster at its poles.
D) There are many sunspots visible on the surface of the Sun.
E) all of the above
D) There are many sunspots visible on the surface of the Sun.
Which of the following is not a method astronomers use to determine the physical conditions inside
the Sun?
A) observing X-ray images of the solar interior using satellites
B) building mathematical models that use the laws of physics
C) detecting solar neutrinos generated in the Sun’s core
D) measuring Doppler shifts to observe solar vibrations
A) observing X-ray images of the solar interior using satellites
What is a solar flare?
A) an ejection of solar material from the corona
B) solar material from the chromosphere following the arches of the Sun’s magnetic field
C) an eruption of solar material from the photosphere
D) the same thing as a filament
E) none of the above
C) an eruption of solar material from the photosphere
n the diagram of the Sun’s interior on the right, some arrows point outward, and some arrows point inward. Long arrows are near the center, short arrows near the outer surface. The arrows in this diagram are meant to show how gravitational equilibrium works in the Sun. What do the different directions and different arrow lengths represent?
A) Inward arrows represent gravity; outward arrows represent the solar wind; longer arrows represent a stronger push or pull.
B) Inward arrows represent gravity; outward arrows represent pressure; longer arrows represent a stronger push or pull.
C) Inward arrows represent downward convection; outward arrows represent upward convection;
longer arrows represent stronger convection.
D) Inward arrows represent convection; outward arrows represent radiation; longer arrows
represent greater intensity.
B) Inward arrows represent gravity; outward arrows represent pressure; longer arrows represent a stronger push or pull.
In the late 1800s, Kelvin and Helmholtz suggested that the Sun stayed hot due to gravitational
contraction. What was the major drawback to this idea?
A) It predicted that the Sun would shrink noticeably as we watched it, but the Sun appears to be
stable in size.
B) It predicted that the Sun could shine for about 25 million years, but geologists had already
found that Earth is much older than this.
C) It is physically impossible to generate heat simply by making a star shrink in size.
D) It predicted that Earth would also shrink in size with time, which would make it impossible to
have stable geology on our planet.
B) It predicted that the Sun could shine for about 25 million years, but geologists had already
found that Earth is much older than this.
Star A and Star B have measured stellar parallax of 0.75 arc second and 0.10 arc second,
respectively. Which star is closer?
A) Star A is closer.
B) Star B is closer.
C) Star A and Star B are the same distance away.
D) Distance cannot be determined from the parallax alone.
A) Star A is closer.
Hydrogen lines are weak in the spectra of hot O-type stars because ____.
A) most of the hydrogen has been converted to helium
B) a good spectrum of these stars is difficult to obtain
C) these stars have no atmosphere
D) gravitational pressure pushes all the hydrogen lines out of the visible spectrum
E) most of the hydrogen is ionized to high energy levels
E) most of the hydrogen is ionized to high energy levels
Which of the following is the most numerous type of main-sequence star?
A) an O star
B) an A star
C) an F star
D) a G star
E) an M star
E) an M star
What eventually halts the gravitational collapse of an interstellar gas cloud that forms an object that
is not massive enough to become a star?
A) the central object becoming hot enough to sustain nuclear fusion in its core
B) the crowding of electrons in the core
C) Nothing; all collapsing gas clouds become black holes.
D) A critical fraction of the gas has been driven further into space.
B) the crowding of electrons in the core
Since all stars begin their lives with the same basic composition, what characteristic is most
important in determining how they will differ?
A) their location in the galaxy
B) the time at which they formed
C) their initial luminosity
D) their initial mass
E) their initial color
D) their initial mass
On the main sequence, stars obtain their energy
A) from chemical reactions.
B) from gravitational contraction.
C) by converting hydrogen to helium.
D) by converting helium to carbon, nitrogen, and oxygen.
E) from nuclear fission.
C) by converting hydrogen to helium.
Which of the following comparisons between low-mass stars and high-mass main-sequence stars is
true?
A) Low-mass stars have the same temperature and luminosity as high-mass stars.
B) Low-mass stars are cooler and less luminous than high-mass stars.
C) Low-mass stars are hotter and more luminous than high-mass stars.
D) Low-mass stars are cooler but more luminous than high-mass stars.
E) Low-mass stars are hotter but less luminous than high-mass stars
B) Low-mass stars are cooler and less luminous than high-mass stars.
What is the main idea captured by the graph on the right?
A) Low-mass stars are much more common than
higher-mass stars.
B) Objects with mass below 0.08 M Sun are brown
dwarfs rather than true stars.
C) Stars are best understood by dividing them into
four categories by mass.
D) Low-mass stars are smaller and redder than
higher-mass stars.
E) Most stars have approximately the same mass as
the Sun.
A) Low-mass stars are much more common than
higher-mass stars.
Which of the following sequences correctly describes the stages of life for a one solar mass star?
A) red giant, protostar, main-sequence, white dwarf
B) white dwarf, main-sequence, red giant, protostar
C) protostar, red giant, main-sequence, white dwarf
D) protostar, main-sequence, white dwarf, red giant
E) protostar, main-sequence, red giant, white dwarf
E) protostar, main-sequence, red giant, white dwarf
Helium fusion directly results in the formation of
A) hydrogen.
B) oxygen.
C) carbon.
D) nitrogen.
E) iron
C) carbon.
