Do not refer to the text when taking this exam. A good score is at least 75 correct. Answers are in the back of the book. It is best to have a friend check your score the first time so that you won’t memorize the answers if you want to take the test again.
1. As seen from temperate or tropical latitudes, the positions of the constellations shift gradually westward in the sky from night to night because
(a) the Earth rotates on its axis.
(b) the Earth revolves around the Sun.
(c) the tilt of the Earth’s axis changes.
(d) their right ascensions constantly change.
(e) their declinations constantly change.
2. A star cluster in which the individual stars do not show a striking central concentration nor an orderly pattern or structure is called
(a) a thin cluster.
(b) an open cluster.
(c) a nebulous cluster.
(d) a globular cluster.
(e) a random cluster.
3. An average star such as our Sun will, it is believed, eventually end up as
(a) a blue dwarf.
(b) a black hole.
(c) a proton star.
(d) a pulsar.
(e) a black dwarf.
4. an imaginary line connecting any planet with the Sun
(a) revolves around the Sun at a constant angular rate.
(b) is always the same length.
(c) is longest when the planet moves fastest.
(d) sweeps out equal areas in equal periods of time.
(e) is constantly getting longer.
(a) is more radioactive than a typical galaxy.
(b) is a galaxy that can be observed only at radio wavelengths.
(c) is a galaxy that emits an unusually large amount of energy at radio wavelengths.
(d) is a galaxy that emits radio signals that sound like they come from an intelligent civilization.
(e) is a galaxy to which we have sent radio signals in the hope of contacting extraterrestrial civilizations.
6. Total internal reflection can occur for a light beam
(a) striking a pane of glass from the outside.
(b) passing through a pane of glass at a right angle.
(c) striking the surface of a prism at a grazing angle from the inside.
(d) traveling from one place to another through a vacuum.
(e) under no circumstances.
7. The distance from the Earth to the Moon is approximately
(a) 3 times Earth’s diameter.
(b) 10 times Earth’s diameter.
(c) 30 times Earth’s diameter.
(d) 100 times Earth’s diameter.
(e) 300 times Earth’s diameter.
8. The nanometer is commonly used to denote
(a) image resolution in a telescope.
(b) diameters of telescope objectives.
(c) focal lengths of telescope eyepieces.
(d) wavelengths of longwave radio signals.
(e) wavelengths of visible light.
9. Why do meteors seem to come from a particular spot in the sky during a meteor shower?
(a) Because they are traveling perpendicular to the Earth’s orbit around the Sun.
(b) Because they move at extreme speed relative to Earth, differences in their actual direction don’t make a significant difference.
(c) It is an illusion; we see them from a certain perspective, although they fall toward Earth in more or less parallel paths.
(d) For good reason! They actually originate in the constellation that seems to produce them.
(e) The premise is wrong. Meteors seem to come from all over the sky during a shower.
10. The celestial meridians all intersect each other at the
(a) celestial equator.
(b) celestial parallels.
(c) celestial poles.
(e) horizon.
11. The solar orbit of Mars lies between the solar orbits of
(a) Mercury and Venus.
(b) Venus and Earth.
(c) Earth and Jupiter.
(d) Jupiter and the asteroids.
(e) Saturn and the asteroids.
12. Ganymede, the largest moon of Jupiter, keeps one face toward the planet at all times because
(a) Jupiter’s powerful magnetic field interacts with Ganymede’s magnetic field to keep Ganymede’s rotation rate in sync with its orbital period.
(b) Ganymede is slightly out of round, and Jupiter’s gravitation takes advantage of this to keep Ganymede’s rotation rate in sync with its orbital period.
(c) Ganymede lies in the plane of Jupiter’s equator, and this sort of orbit always produces synchronization of a satellite’s rotation rate with its orbital period.
(d) of a sheer coincidence.
(e) nothing! Ganymede does not keep the same face toward Jupiter at all times.
13. Distances to some of the galaxies outside the Milky Way have been estimated by observing and measuring the relative magnitudes of
(a) Cepheids.
(b) globular clusters.
(c) blue dwarfs.
(d) neutron stars.
(e) red giants.
14. In an electromagnetic field, the direction of wave travel (propagation) is
(a) parallel to the magnetic lines of flux.
(b) parallel to the electrical lines of flux.
(c) parallel to both the magnetic and the electrical lines of flux.
(d) parallel to neither the magnetic nor the electrical lines of flux.
(e) dependent on the wavelength.
15. The elevation of an object in the sky is its
(a) angle in degrees with respect to the zenith.
(b) angle in degrees with respect to true (geographic) north.
(c) angle in degrees with respect to the meridian.
(d) angle in degrees above the horizon.
(e) distance in kilometers from the Earth.
16. Long-distance space travel will require
(a) an advanced or even an as-yet unknown propulsion system.
(b) patience and cooperation among the spacecraft crew.
(c) a means of replenishing or maintaining food, air, and water supplies.
(d) a shelter against stellar and cosmic radiation.
(e) all of the above.
17. Dust storms on Mars
(a) are too small to be seen by Earth-based telescopes.
(b) occur only near the poles.
(c) never last more than a few hours.
(d) sometimes cover the whole planet.
(e) do not occur. Mars has no atmosphere and therefore no wind.
18. On Earth, there are certain places where the Sun stays above the horizon for 24 hours a day on June 21. These places all lie between
(a) the equator and 23.5°N. latitude.
(b) the equator and 66.5°N. latitude.
(c) the equator and 23.5°S. latitude.
(d) the equator and 66.5°S. latitude.
(e) none of the above.
19. By definition, living things generally
(a) act against entropy.
(b) distribute energy throughout the Cosmos.
(c) produce ionizing radiation.
(d) convert oxygen into carbon dioxide.
(e) give off energy in the form of heat.
20. Suppose that you are located at 45° north latitude. It is late January. At exactly 6:00 P.M. local time, you see a star at the zenith. Where will the star be at 6:00 A.M., 12 hours later?
(a) On the southern horizon
(b) On the northern horizon
(c) On the western horizon
(d) On the eastern horizon
(e) Below the horizon, at the nadir
21. The rate at which time “flows” depends on
(a) absolute position in space.
(b) the intensity of the gravitational field.
(c) the speed of light.
(d) the intensity of Earth’s magnetic field.
(e) all of the above.
22. The Kuiper belt contains an abundance of
(a) radiation from Earth’s magnetic field.
(b) radiation from Jupiter’s magnetic field.
(c) high-speed particles from the Sun.
(d) comets.
(e) meteors and asteroids.
(a) cold, dark, and icy.
(b) an ocean of liquid methane and ammonia.
(c) hot, dry, and under enormous pressure.
(d) a mystery because of the clouds that shroud the planet.
(e) nonexistent; it is a “gas ball” like Jupiter or Saturn.
24. We do not see impact craters on the surface of Jupiter because
(a) Jupiter has no solid surface on which craters can form.
(b) Jupiter’s moons take all the hits from incoming meteors.
(c) Jupiter’s gravitational field protects it from meteors.
(d) Jupiter’s magnetic field deflects meteors.
(e) Jupiter is too far away for our telescopes to resolve craters there.
25. What do Mercury and Venus have in common?
(a) They are both larger than the Earth.
(b) They both lack atmospheres.
(c) They both have retrograde orbits around the Sun.
(d) They both have solar orbits inside the Earth’s solar orbit.
(e) Neither of them ever appears in a crescent phase.
26. In every respect, acceleration force manifests itself in precisely the same way as
(a) the force caused by gravitation.
(b) the force caused by time dilation.
(c) the force caused by high speeds.
(d) the force caused by constant relative motion.
(e) none of the above.
27. As seen through telescopes on Earth, Jupiter appears as a crescent
(a) when it is at or near opposition.
(b) when it is at or near quadrature.
(c) when it is at or near conjunction.
(d) when it is at or near perihelion.
(e) at no time.
28. Distances between stars in our galaxy are generally expressed in
(a) meters.
(b) kilometers.
(c) miles.
(d) light-miles.
(e) light-years.
29. A robotic remote-control system that employs feedback to give the operator a sense of “being the robot” is called
(a) remote synchronization.
(b) telemetry.
(c) telepresence.
(e) time dilation.
30. Fill in the blank to make the following sentence true: “The path that the Sun follows from west to east against the background of stars during the course of the year is a circle in the sky called the _____.”
(a) celestial equator
(b) celestial meridian
(c) solar circle
(d) ecliptic
(e) prime parallel
31. According to the special theory of relativity, a space ship can exceed the speed of light
(a) if it turns into antimatter.
(b) if time is made to run backward.
(c) if antigravity propulsion systems are used.
(d) if space is curved in the vicinity of the vessel.
(e) under no circumstances.
32. Suppose that you live in Dallas, Texas. You see the Moon just after sunset on an evening approximately four days before the new Moon. Which of the following is true?
(a) The Moon appears gibbous and waxing.
(b) The Moon appears gibbous and waning.
(c) The Moon appears crescent and waxing.
(d) The Moon appears crescent and waning.
(e) You must be dreaming. In reality, the Moon is below the horizon.
33. Fill in the blank in the following sentence to make it true: “The special theory of relativity is concerned with relative motion, and the general theory of relativity is concerned with ______.”
(a) black holes and white dwarfs
(b) acceleration and gravitation
(c) space travel
(d) absolute motion
(e) the gravitational collapse of the Universe
34. Which of the following is not a feature of the surface of Mars today?
(a) Mountains of volcanic origin
(b) Canyons that apparently once were rivers
(c) Polar ice caps
(d) Impact craters caused by meteorites
(e) Liquid oceans
35. The number of other advanced civilizations in our galaxy
(a) is probably diminishing with time.
(b) can only be guessed at.
(c) must be small because none of them have paid us a visit.
(d) must be large because there are so many stars.
(e) must be small because we have heard no signals from them.
36. An extremely massive star can collapse until it is so dense that nothing, not even light rays, can escape from its immediate vicinity. This type of object is called
(a) a black dwarf.
(b) a black hole.
(c) a neutron star.
(d) a pulsar.
(e) nothing! There can be no such object.
37. At the north celestial pole, the circumpolar constellations
(a) fill the sky; every constellation you see is circumpolar.
(b) do not exist; no constellation you see is circumpolar.
(c) rise in the east and set in the west, just as they do anywhere else.
(d) never rise above the horizon.
(e) remain fixed in the sky at all times.
38. Virtually all Earth’s weather takes place within the
(a) torrid zone.
(b) temperate zone.
(c) troposphere.
(d) stratosphere.
(e) exosphere.
39. In the Search for Extraterrestrial Intelligence (SETI) program, the 21-cm hydrogen wavelength has received particular attention because
(a) scientists think that alien civilizations would stay away from the corresponding frequency.
(b) scientists think that alien civilizations would be likely to listen for and transmit signals near the corresponding frequency.
(c) that wavelength contains large amounts of EM energy.
(d) the corresponding range of frequencies is vast.
(e) the premise is false. The 21-cm hydrogen wavelength has not received any special attention.
40. The southern pole star is
(a) Canopus.
(b) Crux.
(c) Polaris.
(d) Regulus.
(e) none of the above; there is no southern pole star.
41. The Earth’s axis “wobbles” over long periods, like the axis of a spinning top. This is called
(a) retrograde motion.
(b) libration.
(d) precession.
(e) convolution.
42. When the first pulsar was detected with a radio telescope, some people got the idea that the emissions were coming from
(a) an extraterrestrial civilization.
(b) galaxies blowing up.
(c) Jupiter’s magnetic field.
(d) the Moon.
(e) the Sun.
43. A type E0 galaxy is shaped like
(a) a sphere.
(b) a flat disk.
(c) an irregular blob of stars.
(d) a football.
(e) a cigar.
44. From where on Earth’s surface is every point on the celestial sphere above the horizon at one time or another as Earth makes one complete rotation relative to the stars? (Assume that the terrain is flat so that the horizon is not obstructed by hills, buildings, or anything else.)
(a) Nowhere
(b) Either geographic pole
(c) The geographic equator
(d) Anywhere between the Tropic of Cancer and the Tropic of Capricorn
(e) Anywhere
45. Hubble and Humason believed that the red shifts of distant galaxies are caused by expansion of the Universe. Based on this assumption, they found that the speed-versus-distance function can be graphed as
(a) a bell-shaped curve.
(b) a curve similar to the Main Sequence.
(c) a straight line.
(d) a logarithmic curve.
(e) an exponential curve.
46. Which of the following planets cannot be seen from Earth with the unaided eye?
(a) Neptune
(b) Saturn
(c) Mercury
(d) Canopus
(e) All the planets can be seen from Earth with the unaided eye.
47. A telescope has an objective lens with a diameter of 250 mm. An eyepiece with a focal length of 10 mm is used. What is the magnification?
(a) 25×
(c) 250×
(d) 10×
(e) It cannot be calculated from this information.
48. The diameter of Earth is roughly the same as the diameter of
(a) Mercury.
(b) Venus.
(c) Mars.
(d) Jupiter.
(e) Ganymede.
49. The “hairy” glowing region of a visible a comet, immediately surrounding the core, is known as
(a) the dust tail.
(b) the coma.
(c) the gas tail.
(d) the nucleus.
(e) the atmosphere.
50. Lunar libration is responsible for
(a) the fact that the tides are extreme at certain times and moderate at other times.
(b) the fact that the Moon goes through phases rapidly at certain times of the year and slowly at other times of the year.
(c) the fact that, over time, we can see slightly more than half the Moon’s surface.
(d) the fact that the Moon is sometimes a little closer to Earth than at other times.
(e) the fact that the Moon affects certain people’s moods, particularly when it is at perigee and it is full.
51. Which of the following stars or constellations can be seen in the southern sky on winter evenings by people who live in the northern hemisphere at temperate latitudes?
(a) Ursa minor
(b) Ursa major
(c) Polaris
(d) Cassiopeia
(e) None of the above
52. In order to read star charts on a dark night without desensitizing your eyes too much, you can use
(a) candles.
(b) a dim source of red light.
(c) a dim source of blue light.
(d) a dim source of black light (ultraviolet).
(e) a cathode-ray-tube (CRT) computer monitor.
53. A runaway greenhouse effect is believed responsible for the hellish environment of
(a) the Moon.
(b) Mars.
(c) Jupiter.
(d) Venus.
(e) Pluto.
54. Neptune has a moon called
(a) Phobos.
(b) Callisto.
(c) Europa.
(d) Triton.
(e) Charon.
55. Which of the following planets or moons has a specific gravity less than that of liquid water?
(a) The Moon
(b) Mars
(c) Saturn
(d) Titan
(e) Ganymede
56. The nuclei of atoms heavier than hydrogen contain
(a) protons, neutrons, and electrons.
(b) protons and neutrons.
(c) neutrons and electrons.
(d) protons and electrons.
(e) protons only.
57. A total eclipse of the Sun occurs when
(a) the Moon passes between Earth and the Sun and the Moon is at apogee.
(b) The Moon passes between Earth and the Sun and the Moon is at perigee.
(c) Earth passes between the Moon and the Sun and the Moon is at apogee.
(d) Earth passes between the Moon and the Sun and the Moon is at perigee.
(e) Earth, the Moon, and the Sun line up at any time.
58. In an H-R diagram, most stars are found along or in the
(a) bell-shaped curve.
(b) median curve.
(c) Main Sequence.
(d) lower-left corner.
(e) upper-right corner.
59. The density of a pulsar is approximately the same as the density of
(a) Earth.
(b) the Moon.
(c) Jupiter.
(e) none of the above.
60. The moons of Mars
(a) are nonexistent; Mars has no moons.
(b) are tiny compared with the planet.
(c) are significant in size compared with the planet.
(d) are volcanically active.
(e) revolve around the planet in polar orbits.
61. What is the right ascension of the Sun at the summer solstice in the northern hemisphere?
(a) 0 h
(b) 6 h
(c) 12 h
(d) 18 h
(e) It cannot be determined without more information.
62. The volcanoes on Io, one of Jupiter’s moons, occur because
(a) Io is under constant tidal stress because of Jupiter’s gravitation.
(b) Io is bombarded by subatomic particles because of Jupiter’s magnetic field.
(c) Io is subjected to powerful magnetic forces from Jupiter.
(d) Io was just “born that way.”
(e) Io is less dense than most other celestial objects.
63. The orbit of the Pluto-Charon system crosses the orbit of the Neptune-Triton system. However, astronomers believe that Pluto-Charon and Neptune-Triton will never collide because
(a) space is just too vast; the probability is in effect zero.
(b) the orbital periods of the two systems are in resonance, so they always miss each other.
(c) the orbits of the two systems are not in the same plane.
(d) the solar orbit of the Pluto-Charon system is retrograde, whereas the solar orbit of the Neptune-Triton system is prograde.
(e) nothing! Astronomers believe the two systems will collide.
64. According to Ptolemy’s geocentric theory, the orbits of the planets consisted of two elements called
(a) radius and circumference.
(b) celestial latitude and celestial longitude.
(c) right ascension and declination.
(d) deferent and epicycle.
(e) nothing! Ptolemy never formulated a geocentric theory.
65. The Sun derives its energy from
(a) combustion.
(b) nuclear fission.
(d) matter-antimatter reactions.
(e) all of the above.
66. According to geocentric theories,
(a) Earth revolves around the Sun.
(b) Earth is the center of the Universe.
(c) Earth’s motion is relative.
(d) the center of Earth is the source of all energy.
(e) the stars are mere illusions.
67. The objective in a reflecting telescope is
(a) a convex mirror.
(b) a concave mirror.
(c) a convex lens.
(d) a concave lens.
(e) a planoconcave lens.
68. The star Rigel is a feature of the evening sky in January for viewers at 45° north latitude; it is fairly high in the southern sky. For viewers at 45° south latitude,
(a) Rigel is seen in the evening sky in July; it is fairly high in the north.
(b) Rigel is seen in the evening sky in July; it is fairly high in the south.
(c) Rigel is seen in the evening sky in January; it is fairly high in the north.
(d) Rigel is seen in the evening sky in January; it is fairly high in the south.
(e) Rigel is never seen at all.
69. Massive black holes are believed to be common
(a) in the cores of stars.
(b) in orbits around planets.
(c) at the centers of galaxies.
(d) at the centers of open star clusters.
(e) in the arms of spiral galaxies.
70. According to the theory of natural selection, life forms, if given enough time, will evolve in such a way that they
(a) get more and more biologically simple.
(b) have longer and longer individual life spans.
(c) become better suited to the environment in which they live.
(d) all converge toward a single, universal species.
(e) become more and more hostile to each other.
71. A simple objective lens refracts orange light to a slightly different extent than it refracts blue light. This is observed in a telescope as
(a) partial internal refraction.
(b) selective refraction.
(c) chromatic aberration.
(d) coma.
(e) astigmatism.
72. On Mars, your weight would be
(a) less than your weight on Earth but more than your weight on Jupiter.
(b) less than your weight on Earth but more than your weight on an asteroid.
(c) more than your weight on Earth but less than your weight on Neptune.
(d) more than your weight on Earth but less than your weight on Saturn.
(e) the same as your weight on Earth.
73. In order to obtain the speeds necessary for interstellar travel, nuclear bombs have been suggested as a method of producing thrust. A practical problem with this scheme is the fact that
(a) nuclear bombs would be too heavy to carry.
(b) the impulse would occur in uncomfortable bursts.
(c) a source of oxygen would be needed.
(d) great quantities of water would be required.
(e) the explosions would irradiate the food supply.
74. Which of the following theories concerning the origin of the Solar System is most commonly accepted?
(a) The planets formed from a black hole that sucked gas and dust into orbit around itself from a large region of interstellar space.
(b) The planets formed when a passing star ripped matter out of the Sun.
(c) The planets and Sun formed from a condensing disk of interstellar gas and dust.
(d) The planets formed from comets that fell into the Sun, causing solar matter to be ejected into space.
(e) The planets and Sun formed from a white hole, that is, a place where new matter was introduced from another universe.
75. The velocity (speed and direction) of a meteor as it enters the Earth’s atmosphere can be measured accurately using
(a) a high-powered telescope.
(b) binoculars.
(c) radar.
(d) an interferometer.
(e) a spectrograph.
76. If intelligent civilizations in the Cosmos always become warlike, we should not expect to get any visits from them because
(a) they look at us and think we are too weak to bother with.
(b) they are afraid of us because we are so barbaric.
(c) they have already conquered us; we just don’t realize it yet.
(d) they annihilate themselves before they become capable of visiting us.
(e) none of the above; we ought to expect them any time.
77. A converging lens
(a) brings parallel light rays to a focus.
(b) spreads parallel light rays out.
(c) makes converging light rays parallel.
(d) can do any of a, b, and c.
(e) can do none of a, b, or c.
78. Which of the following planets has no known moons?
(a) Mercury
(b) Mars
(c) Uranus
(d) Neptune
(e) Pluto
79. The carbon dioxide produced by human respiration in an interstellar space ship could be used by
(a) the nuclear propulsion system.
(b) the radiation shield.
(c) the water-electrolysis equipment.
(d) plants grown for food.
(e) nothing; it could serve no useful purpose.
80. The interferometer is a form of
(a) refracting telescope.
(b) spectrograph.
(c) high-resolution radio telescope.
(d) x-ray camera.
(e) device for measuring red shift.
81. Which of the following planets lacks a ring system?
(a) Jupiter
(b) Saturn
(c) Uranus
(d) Neptune
(e) All of the above planets have ring systems.
82. Approximately how far is the Moon from Earth?
(a) 1.3 light-seconds
(b) 250,000 light-seconds
(c) 400,000 light-seconds
(d) 8.2 light-minutes
(e) 4.3 light-years
83. An angle that measures 120 seconds of arc is the same as an angle that measures
(a) 2 minutes of arc.
(b) 2 degrees of arc.
(c) 7,200 minutes of arc.
(d) one-third of a circle.
(e) two complete circles.
84. Meteorites are always found
(a) in solar orbit between Mars and Jupiter.
(b) in solar orbit.
(c) in Earth orbit.
(d) in lunar orbit.
(e) on Earth’s surface.
85. The f-ratio of a telescope is the
(a) diameter of the objective divided by the diameter of the eyepiece in the same units.
(b) eyepiece focal length divided by the objective focal length in the same units.
(c) objective focal length divided by the eyepiece focal length in the same units.
(d) objective focal length divided by the objective diameter in the same units.
(e) none of the above.
86. If you observe the sky from the southern tip of South America, which of the following constellations will you never see?
(a) Crux
(b) Carina
(c) Grus
(d) Ursa Minor
(e) You will never see any of the above.
87. A Barlow lens can be useful for
(a) increasing the number of magnification levels obtainable with a given set of telescope eyepieces.
(b) obtaining extreme magnification for looking at the details of distant stars and galaxies.
(c) reducing the effective focal length of a telescope’s objective.
(d) eliminating chromatic aberration in reflecting telescopes.
(e) increasing the apparent field of view for a particular telescope eyepiece.
88. As the wavelengths of x-rays become shorter, it gets increasingly difficult to direct and focus them because
(a) they become fainter.
(b) their penetrating power increases.
(c) their frequency decreases.
(d) they are increasingly affected by magnetic fields.
(e) nothing! The premise is false. It gets easier to focus x-rays as their wavelengths become shorter.
89. A full-aperture solar filter
(a) screws into the barrel of a telescope eyepiece.
(b) is used with telescope finders only.
(c) attaches to the secondary mirror in a reflecting telescope.
(d) keeps direct, unfiltered sunlight entirely out of a telescope.
(e) should never be used with any telescope.
90. Under what circumstances is the shortest distance between two points a curve rather than a straight line?
(a) Under no circumstances
(b) When space is “flat”
(c) When two observers are moving relative to each other at constant speed
(d) In the presence of a powerful gravitational field
(e) Whenever clocks are not synchronized
91. A Moon filter can improve the image of
(a) a crescent Moon viewed at high magnification.
(b) a full Moon viewed at low magnification.
(c) a crescent Moon viewed with a Barlow lens.
(d) a new Moon viewed with a focal reducer/corrector.
(e) the Moon at any phase viewed with a short-focal-length eyepiece.
92. The full phase of Mercury, as seen through telescopes on Earth, takes place when the planet is near
(a) opposition.
(b) inferior conjunction.
(c) quadrature.
(d) superior conjunction.
(e) perihelion.
93. If the Pluto-Charon system had been discovered today rather than many years ago, some astronomers would classify it as
(a) a pair of large asteroids.
(b) a pair of huge comets.
(c) a pair of tiny, unborn stars.
(d) a pair of errant moons of Neptune.
(e) a pair of objects outside the Solar System.
94. Fill in the blank in the following sentence to make it true: “Quasars exhibit _______ in their spectral lines.”
(a) stability
(b) blurring
(c) blue shifts
(d) red shifts
(e) alternating red and blue shifts
95. Titan, the largest moon of Saturn, has an atmosphere that is
(a) much colder than that of Earth.
(b) much warmer than that of Earth.
(c) plagued by constant dust storms.
(d) rich in hydrogen and filled with blue-white clouds of water vapor.
(e) similar to the atmosphere of Earth.
96. Earth is closest to the Sun during the month of
(a) January.
(b) May.
(c) July.
(d) September.
(e) November.
97. Suppose that the spectral lines in the light from a star shift at a regular rate toward the red, then toward the blue, then back toward the red, and so on. What can we surmise about this star?
(a) It is receding from us.
(b) It is approaching us.
(c) It is in orbit around or is in mutual orbit with something.
(d) Its temperature varies on a regular basis.
(e) Its brightness varies on a regular basis.
98. Fill in the blank to make the following sentence true: “According to Kepler, each planet follows an elliptical orbit around the Sun, with the Sun ___________.”
(a) at the center of the ellipse
(b) outside the ellipse
(c) on the minor axis of the ellipse
(d) at one focus of the ellipse
(e) between the two foci of the ellipse
99. The brightest star in the entire sky is
(a) Canis Minor.
(b) Andromeda.
(c) Polaris.
(d) Rigel.
(e) Sirius.
100. A person living in Perth, Australia, gets the most daylight during the month of
(a) December.
(b) March.
(c) June.
(d) September.
(e) Any of the above; they’re all the same.