# Astronomy Related Multiple Choice Questions With Answers – Part 1

It is natural to imagine to sky as a dome or sphere at the center of which we, the observers, are situated. This notion has always been, and still is, used by astronomers to define the positions of objects in the heavens.

This article is for people who want to learn basic astronomy without taking a formal course. It also can serve as a supplement knowledge in a classroom, tutored or home-schooling environment.

This article contains an abundance of practice quiz, test and exam questions. They are all multiple choice questions and are similar to the sorts of questions used in standardized tests.

1. Which of the following points or objects seems to stay fixed in the sky all the time?

(a) The vernal equinox
(b) The background of stars
(c) The Sun
(d) Polaris

2. What is the declination represented by the south celestial pole?

(a) 18 h
(b) 0°
(c) -90
(d) It cannot be defined because it changes with time.

3. What is the celestial longitude of the winter solstice?

(a) 18 h
(b) 0°
(c) -90
(d) It cannot be defined because it changes with time.

4. A point is specified as having a celestial latitude of 45°30,00″N. This is equiv alent to how many degrees as a decimal fraction?

(a) 45.5°
(b) 45.3°
(c) 30.00°
(d) There is not enough information to tell.

5. How many hours of right ascension correspond to one-third of a circle?

(a) 3h
(b) 6h
(c) 12 h
(d) None of the above

6. How many sidereal days are there in one full calendar year?

(a) Approximately 366.25
(b) Approximately 365.25
(c) Approximately 364.25
(d) It depends on the celestial latitude of the observer.

7. One second of arc represents what fraction of a complete circle?

(a) 1/60
(b) 1/3600
(c) 1/86,400
(d) 1/1,296,000

8. The celestial latitude/longitude frame of reference

(a) Is fixed relative to the background of stars.
(b) Is fixed relative to the Sun.
(c) Is fixed relative to geostationary satellites.
(d) Is not fixed relative to anything.

9. Which of the following represents an impossible or improperly expressed coordinate value?

(a) RA = 12h
(b) Dec = +100
(c) 103 deg 00 min 20 sec W long
(d) 23°S

10. Azimuth is another name for

(a) Right ascension.
(b) Compass bearing.
(c) celestial latitude.
(d) Celestial longitude.

11. Counterclockwise around the north celestial pole from night to night because

(a) Bootes and Canes Venatici chase Ursa Major around Polaris.
(b) The sidereal day is slightly shorter than the solar day.
(c) Earth rotates on its axis.
(d) The galaxy spirals around its center.

12. If you live in the northern hemisphere, the elevation of Polaris above the hori¬zon, in degrees, is about the same as

(b) 90 degrees minus your latitude.
(c) The elevation of the Sun in the sky at noon.
(d) Nothing in particular; its elevation changes as the seasons pass.

13. Tau Ceti is considered a special star because

(a) It revolves around Polaris in a perfect circle.
(b) It is inside our solar system.
(c) It is in a constellation all by itself.
(d) Some astronomers think that it might have a solar system like ours.

14. Earth slowly wobbles on its axis, causing the constellations to

(a) Change shape slightly from year to year.
(c) Shift position in the sky slightly from century to century.
(d) Follow the plane of the ecliptic.

15. People in the time of Julius Caesar saw constellations whose individual shapes were

(a) The same as they are now.
(b) Somewhat different than they are now.
(c) Almost nothing like they are now.
(d) Nothing at all like they are now.

16. The constellation Andromeda is well known because it contains

(a) The brightest star in the whole sky.
(b) All the planets at one time or another.
(c) The north celestial pole.
(d) A spectacular spiral galaxy.

17. Orion is a landmark constellation in the northern hemisphere

(a) all year round.
(b) During the winter.
(c) Only north of about 45 degrees latitude.
(d) Because it contains the brightest two stars in the sky.

18. Coma Berenices is sometimes mistaken for

(a) The sword of Orion.
(b) Ursa Major.
(c) The Andromeda galaxy.

19. The pole star, Polaris, is part of

(a) Canis Major.
(b) Pegasus.
(c) Ursa Minor.
(d) No constellation; it stands by itself.

20. The stars Vega, Altair, and Deneb dominate the sky

(a) in the circumpolar region.
(b) During the northern hemisphere summer.
(c) During spring, summer, and fall, respectively.
(d)No these are not stars but constellations.

21. In the southern hemisphere, elevation is measured in the same way as it is in the northern hemisphere, with the following exception:

(a) It is a negative angle rather than a positive angle.
(b) It is expressed in radians rather than in degrees.
(c) It is measured with respect to the South Pole rather than the north pole.
(d) There are no exceptions.

22. Which of the following stars is also known as “south Polaris”?

(a) Formalhaut
(b) Capella
(c) Sirius
(d) None of the above

23. The spring equinox in the southern hemisphere occurs in which month?

(a) March
(b) June
(c) September
(d) December

24. Suppose that it is a few days after the summer solstice according to people who live in Sydney, Australia, The Sun’s declination is

(a) Slowly decreasing.
(b) Rapidly decreasing.
(c) Slowly increasing.
(d) Rapidly increasing.

25. At a latitude of 35°S, the angular radius of the south circumpolar region is

(a) 70 degrees of arc.
(b) 55 degrees of arc.
(c) 35 degrees of arc.
(d) Impossible to determine, not enough data are given.

26. Orion is a landmark constellation primarily in which season south of the equator?

(a) Winter
(b) Summer
(c) Spring
(d) Fall

27. At a latitude of 55°S, the northern pole star Polaris would be approximately

(a) 35 degrees above the horizon.
(b) 35 degrees below the horizon.
(c) 55 degrees above the horizon.
(d) 55 degrees below the horizon.

28. A circumpolar constellation as viewed from Cape Town, South Africa, is

(a) Ursa Minor.
(b) Octans.
(c) Ursa Major.
(d) Draco.

29. A star that lies on the celestial equator as seen from 45°N would lie approximately where as seen from 45°S?

(a) On the celestial equator
(b) Near the north celestial pole
(c) Near the south celestial pole
(d) The answer cannot be determined from the information given.

30. As the night progresses for an observer in Buenos Aires, zArgentina, the south circumpolar stars seem to

(a) Revolve counterclockwise around the south celestial pole.
(b) Revolve clockwise around the south celestial pole.
(c) Rise in the east and set in the west.
(d) Never rise above the horizon.

31. The rotational period of the Sun

(a) Is synchronized with the orbit of Earth.
(b) is shorter at the equator than at the poles.
(c) varies in an 11-year cycle.
(d) is not defined; the Sun does not rotate at all.

32. Which of the following theories concerning the Moon’s formation is most popular?

(a) The Moon condensed from the ejecta of thousands of earthly volcanoes many millions of years ago.
(b) The Moon spun off Earth because of centrifugal force when Earth was in its early, molten state.
(c) The Moon and Earth formed as a double planet.
(d) All three of the preceding theories have been disproven conclusively.

33. Eclipses would be more common if the Moon’s orbit

(a) Were more tilted with respect to the plane of the ecliptic.
(b) Were in the plane of the ecliptic.
(d) Were more elongated.

34. The northern lights owe their existence to

(a) Earth’s magnetic field.
(b) Charged particles ejected from the Sun.
(c) Solar flares.
(d) More than one of the above.

35. On a particular day, the Moon sets around high noon. What phase is the Moon in or near?

(a) New
(b) First quarter
(c) Full
(d) Last quarter

36. The composite tidal pull of the Sun and Moon is greatest when

(a) Earth, the Sun, and the Moon are at the vertices of an equilateral triangle.
(b) Earth, the Sun, and the Moon all lie along the same straight line.
(c) Earth, the Sun, and the Moon are at the vertices of a right triangle.
(d) This question is irrelevant; the composite tidal pull of the Sun and the Moon never varies.

37. Earth is

(a) About 81 times more massive than the Moon.
(b) About 10 times the diameter of the Moon.
(c) Always in full phase as seen from the Moon.
(d) The same angular diameter as the Sun, as seen from the Moon.

38. In an annular eclipse of the Sun,

(a) The path of totality is narrow.
(b) The Sun’s disk is totally covered for only a few minutes.
(c) The Sun’s disk is never totally covered.
(d) The Moon takes on a copper-colored glow.

39. Suppose that a small stone with a mass of 10 grams and a large boulder with a mass of 10,000 kilograms are both put into circular orbits 15,000 kilometers above Earth’s surface. Which of the following statements is true?

(a) The stone will take longer to orbit Earth than the boulder.
(b) The boulder will take longer to orbit Earth than the stone.
(c) The stone and the boulder will take the same amount of time to orbit Earth.
(d) The relative orbital periods will depend on how close together the stone and the boulder are placed.

40. The sidereal lunar orbital period (around Earth) is

(a) Longer than the synodic lunar orbital period.
(b) The same as the synodic lunar orbital period.
(c) Shorter than the synodic lunar orbital period.
(d) Sometimes longer than and sometimes shorter than the synodic lunar orbital period.

41. In one day on Earth, the upper equatorial clouds of Venus

(a) Travel about one-quarter the way around the planet.
(b) Travel about one-half the way around the planet.
(c) Travel all the way around the planet.
(d) Travel twice around the planet.

42. The “seasons” on Mercury are caused mainly by

(a) The tilt of the planet’s axis.
(b) The clouds that cover the planet most of the time.
(c) The greenhouse effect.
(d) The difference between perihelion and aphelion.

43. Excellent conditions for observing Mercury occur when the planet

(a) Is at inferior conjunction.
(b) Is at superior conjunction.
(c) Is at opposition.
(d) None of the above

44. When Mercury or Venus is at its greatest elongation either east or west, approximately how much of the surface do we see illuminated?

(a) None of it
(b) Half of it
(c) Three-quarters of it
(d) All of it

45. Mercury is

(a) Smaller than the Moon.
(b) The same size as the Moon.
(c) Larger than the Moon but smaller than Earth.
(d) The same size as Earth.

46. Mercury’s core is almost certainly made up primarily of

(a) Silicate rock.
(b) Iron.
(c) Volcanic lava.
(d) Uranium.

47. High noon on Venus would be just about as bright as

(a) The brightest midday on Mercury.
(b) A typical day on the Moon.
(c) A sunny summer afternoon on Earth.
(d) A gloomy winter day on Earth.

48. The greenhouse effect

(a) Increases a planet’s surface temperature.
(b) Reduces a planet’s surface temperature.
(c) Increases the radiation that reaches a planet’s surface from the Sun.
(d) Keeps heat energy from reaching a planet’s surface.

49. If either Mercury or Venus were to transit the Sun, to which lunar phase would its appearance most nearly correspond?

(a) Full
(b) First quarter
(c) New
(d) Last quarter

50. Which gas is the most abundant in the atmosphere beneath the clouds of Mercury?

(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
(d) This is an improper question; Mercury has no clouds.

51. If the Martian day were divided into 24 hours of equal length, then one Mars hour would be approximately how long?

(a) A little shorter than an Earth hour
(b) Exactly the same as an Earth hour
(c) A little longer than an Earth hour
(d) Variable, depending on the time of year

52. The mean orbital radius of Mars is

(a) About two-thirds that of Earth.
(b) About the same as that of Earth.
(c) About 1.5 times that of Earth.
(d) About twice that of Earth.

53. Suppose that an object has a weight of 50 pounds on Mars. On Earth it would weigh approximately

(a) 18 pounds.
(b) 37 pounds.
(c) 74 pounds.
(d) 135 pounds.

54. Photos appears to traverse the Martian sky from west to east because

(a) Phobos’ orbital period is less than Mars’ rotational period.
(b) Phobos’ orbital period is greater than Mars’ rotational period.
(d) That’s not true! Phobos traverses the Martian sky from east to west.

55. In terms of size, Mars is

(a) Larger than the Moon but smaller than Mercury.
(b) Larger than Mercury but smaller than Earth.
(c) Larger than Venus but smaller than Earth.
(d) Larger than Earth.

56. With respect to its orbit around the Sun, the equatorial plane of Mars is

(a) On a level.

57. The smaller of the two Martian moons is called

(a) Deimos.
(b) Phobos.
(c) Olympus Mons.
(d) Pagonis Mons.

58. Suppose that you stand at the Martian equator when the planet’s north pole is at its maximum tilt away from the Sun (that is, the Sun’s declination is the most negative). The Sun will rise

(a) Directly in the east.
(b) Somewhat south of east.
(c) Somewhat north of east.
(d) In the west.

59. Volcanoes can build up to larger size on Mars than they can on Earth because

(a) The Martian crust does not float around in plates on the mantle the way Earth’s crust does.
(b) Mars has a more intense gravitational field than does Earth.
(c) The atmosphere of Mars is thinner than that of Earth.
(d) This statement is not true! Volcanoes on Mars never get as big as the volcanoes on Earth.

60. Mars appears as a crescent through a small telescope as viewed from Earth

(a) When it is near inferior conjunction.
(b) When it is near superior conjunction.
(c) When it is near opposition.
(d) At no time.

61. Which of the following planets generates the least amount of internal heat?

(a) Jupiter
(b) Saturn
(c) Uranus
(d) Neptune

62. The Pluto Charon system is unique in that

(a) They always keep the same sides facing each other.
(b) They are the smallest of the gas giants.
(c) They have atmospheres consisting entirely of helium.
(d) They actually orbit Neptune, not the Sun.

63. The dark side of Uranus is much colder than the sunlit side because

(a) The axis of Uranus is so greatly tilted.
(b) The atmosphere is so thin.
(c) There are no winds on Uranus.
(d) No! The dark side of Uranus is just as warm as the sunlit side.

64. Most astronomers believe that the surfaces of the gas giant planets

(a) Are liquid water.
(b) Are liquid methane.
(c) Do not exist as definable boundaries.
(d) Are peppered with craters.

65. The tops of the highest clouds on Jupiter

(a) Sunlight very well.
(b) Are red or brown.
(c) Spin counterclockwise because they are high-pressure systems.
(d) Are actually smoke from volcanic eruptions.

66. An Earthly analog of Jupiter’s Great Red Spot might be

(b) A hurricane.
(c) A high-pressure system.
(d) A volcano.

67. Saturn appears in its crescent phase, as seen from Earth, when it is at

(a) Conjunction.
(c) Opposition.
(d) No! Saturn never appears as a crescent to Earth-bound observers.

68. The magnetosphere of Jupiter is distorted by

(a) The solar wind.
(b) Jupiter’s gravitation.
(c) Jupiter’s rings.
(d) Jupiter’s moons.

69. The most oblate planet is

(a) Jupiter.
(b) Saturn.
(c) Uranus.
(d) Neptune.

70. An astronomical unit is

(a) The mean distance of Earth from the Sun.
(b) 299,792 kilometers (one light-second).
(c) The mean distance of the Moon from Earth.
(d) The radius of the Solar System.

71. The Earth’s atmosphere at the surface consists of

(a) 21 percent oxygen.
(b) 78 percent oxygen.
(c) 1 percent carbon dioxide.
(d) 1 percent ozone.

72. At which of the following latitudes would an observer see the Sun for 24 hours a day during some parts of the year?

(a) 50°N.
(b) 23.5°N.
(c) 45°S.
(d) 75°S.

73. The Earth travels most rapidly in its orbit around the Sun during the month of

(a) January.
(b) April.
(c) July.
(d) October.

74. The Earth’s core is believed to be

(a) Extremely cold.
(b) a rarefied gas.
(c) Comprised of basaltic rock.
(d) Ferromagnetic.

75. The Earth’s axis completes one complete cycle of precession approximately every

(a) 18,000 years.
(b) 12,900 years.
(c) 25,800 years.
(d) 50,000 years.

76. The crust of the Earth is thickest

(a) Under continents.
(b) Under the oceans.
(c) In the Polar Regions.
(d) No! The Earth’s crust is uniformly thick everywhere.

77. Because of the generally clockwise flow of waters in the nor them-hemispheric oceans

(a) The U.S. West Coast gets a warm equatorial current.
(b) The U.S. East Coast gets a cold polar current.
(c) The coast of China gets a warm equatorial current.
(d) The western coast of southern Africa receives a warm equatorial current.

78. Temperatures over the ocean do not change very much between day and night because

(a) The ocean heats and cools slowly so that it tends to keep the air tempera true over it fairly constant between day and night.
(b) Land masses radiate heat into the atmosphere at night, where it travels over the oceans and keeps the air there from cooling off.
(c) The salt in the oceans regulates the temperature.
(d) No! Temperatures over the ocean change greatly between day and night.

79. The chemical formula for ozone is

(a) O2.
(b) NO2.
(C) O3.
(d) Co2.

80. High- and low-pressure weather systems in the atmosphere are carried from west to east at temperate latitudes by the

(a) Oceanic currents.
(b) Stratosphere.
(c) Ionized layers.
(d) Jet streams.

81. Imagine an alien star system in which Planet X has a mean orbital radius of 100 million (108) km from Star S and Planet Y has a mean orbital radius of 2 X 10“ km from Star S (twice the mean orbital radius of Planet X). Suppose that the “year” for Planet X is equal to exactly one-half Earth year (0.500 yr). How long is the “year” for Planet Y?

(a) 2.000 years
(b) 1.414 years
(c) 1.000 year
(d) It can’t be figured out from this information.

82. The imperfections in Ptolemy’s theory were “corrected,” without rejecting the whole theory, by

(a) Adding epicycles within epicycles until the theory fit observed facts.
(b) Placing the Moon at the center of the Solar System.
(c) Ignoring the distant stars.
(d) Considering all the planets except Earth to orbit the Sun.

83. The planet Saturn orbits the Earth according to

(a) The geocentric theory.
(b) The heliocentric theory.
(c) Kepler’s theory.
(d) Newton’s theory.

84. Which of the following is not a good argument against the tidal theory?

(a) The planets all orbit the Sun in nearly the same plane.
(b) The planets all orbit the Sun in the same direction.
(c) Stars can never pass so close that they pull matter from each other.
(d) None of the planets have extremely elongated orbits.

85. How likely is it that being like us exist elsewhere in the Milky Way galaxy?

(a) Not likely
(b) Somewhat likely
(c) Very likely
(d) This is a meaningless question. Either there are such beings or there aren’t.

86. Which of the following statements is implied by Kepler’s laws?

(a) A planet moves fastest in its orbit when it is farthest from the Sun.
(b) Planets far from the Sun take longer to complete their orbits than planets closer to the Sun.
(c) All the planets’ orbits lie in exactly the same plane.
(d) All the planets’ orbits are perfect circles.

87. According to the Big Bang theory of Solar System formation,

(a) The planets formed when the primordial Sun exploded, casting some of its matter into space.
(b) The planets evolved from a rotating cloud of gas and dust.
(c) The planets were formed from matter ejected from a huge solar volcano.
(d) Forget it! There is no Big Bang theory of Solar System formation.

88. According to one theory, Uranus has an axis that is tilted to such a great extent because

(a) The planet was not massive enough for its equator to align itself with the plane of its orbit.
(b) A large primordial object smashed into Uranus and tipped it over.
(c) Sooner or later such a tilt will be exhibited by all the planets.
(d) The gravitational effect of Neptune pulled the axis of Uranus out of kilter.

89. For publishing his theories in the sixteenth century, Giordano Bruno was

(a) Knighted by the Queen of England.
(b) Made the official astronomer of the Vatican.
(c) Ignored.
(d) Executed.

90. When the earliest models of the Solar System were formulated, the most distant known planet was

(a) Mars.
(b) Jupiter.
(c) Saturn.
(d) Uranus.

91. Most planetary moons rotate on their axes

(a) Once for every orbit they complete around their parent planets.
(c) Perpendicular to the axes of their parent planets.
(d) in synchronicity with the parent planet’s rotation on its axis.

92. The greatest danger that will face astronauts who plan to visit any of the inner moons of Jupiter or Saturn is

(a) The parent planet’s radiation belts.
(b) The moon’s gravitation.
(c) The moon’s lack of an atmosphere.
(d) The lack of sufficient visible light.

93. Tethys and Mimas are notable because they

(a) Orbit each other.
(b) Are in orbital resonance with each other.
(d) Both have exceptionally high albedo.

94. Continuous, moon wide volcanic activity is observed on

(a) Ganymede.
(b) Io.
(c) Charon.
(d) No planetary satellite.

95. Umbriel is a moon of

(a) Jupiter.
(b) Saturn.
(c) Uranus.
(d) Neptune.

96. Which of the following is a Galilean moon of Saturn?

(a) Ganymede
(b) Titan
(c) Triton
(d) There are no Galilean moons of Saturn.

97. The Lagrange points in a satellite’s orbit are the result of

(b) Volcanic activity on the parent planet.
(c) Thermal heating from inside the satellite.
(d) Gravitational interaction.

98. Which of the following moons is noted for its difference in albedo between the leading side and the trailing side?

(a) Charon
(b) Titan
(c) Impetus
(d) Callisto

99. The plantary moon with the most extensive atmosphere is

(a) Titan.
(b) Charon.
(c) Deimos.
(d) Rhea.

100. On the surfaces of moons of the outer planets, water ice has a hardness and consistency similar to that of

(a) Molasses at room temperature.
(b) Putty at room temperature.
(c) Rock at room temperature.
(d) Steel at room temperature

1. D
2. C
3. D
4. A
5. D
6. A
7. D
8. C
9. B
10. B
11. B
12. A
13. D
14. C
15. A
16. D
17. B
18. D
19. C
20. B
21. D
22. D
23. C
24. C
25. C
26. B
27. D
28. B
29. A
30. B
31. B
32. C
33. B
34. D
35. D
36. B
37. A
38. C
39. C
40. C
41. A
42. D
43. D
44. B
45. C
46. B
47. D
48. A
49. C
50. D
51. C
52. C
53. D
54. A
55. B
56. B
57. A
58. B
59. A
60. D
61. C
62. A
63. D
64. C
65. A
66. C
67. D
68. A
69. B
70. A
71. A
72. D
73. A
74. D
75. C
76. A
77. C
78. A
79. C
80. D
81. B
82. A
83. A
84. C
85. D
86. B
87. D
88. B
89. D
90. C
91. A
92. A
93. B
94. B
95. C
96. D
97. D
98. C
99. A
100. C