1. Which of the following types of radiation are blocked by the Earth's atmosphere?
a) Optical, parts of the infrared.
b) Ultraviolet, Radio, parts of the infrared.
c) Ultraviolet, X-ray, Gamma-ray, parts of the infrared.
d) Radio, Optical.
e) X-ray, Radio, parts of the infrared.

2. Which of the following moons are bigger than Mercury?
a) The Moon, Io.
b) The Moon, Ganymede.
c) Titan, Triton.
d) Ganymede, Titan.
e) Europa, Io.

3. Which of the following objects often do NOT orbit the Sun in or near the ecliptic?
a) The asteroids.
b) Uranus and Venus.
c) The comets.
d) Mars.
e) Neptune.

4. The sixth largest object in our solar system is (in terms of diameter) (counting the Sun as number 1):
a) Ganymede
b) Titan
c) The Earth
d) Uranus
e) Neptune

5. The SECOND largest moon in our solar system (in terms of diameter) is:
a) The Moon.
b) Callisto.
c) Ganymede.
d) Titan.
e) Triton.

6. The largest moon of Neptune is:
a) Io.
b) Europa.
c) Callisto.
d) Titan.
e) Triton.

7. The Earth has an average density of 5.5 g/cm³, while the average density of rocks on its surface is about 3 g/cm³ and the density of water is 1 g/cm³. What conclusion can be reached about the Earth's interior based on these observations?
a) the interior is composed of mainly hydrogen and helium, like the Universe as a whole.
b) it contains a lot of material denser than rock, probably metals.
c) it consists of lower density material than rocks.
d) it is mainly water.
e) it is mainly rocks, like those on the surface.

8. The main reason for combining many widely-separated telescopes together into an interferometer is:
a) To collect more radiation from very faint sources.
b) To obtain much sharper images of sources.
c) To ensure that observations are uninterrupted by the failure of one telescope.
d) To avoid light pollution.
e) To track objects as they move across the sky.

9. Which of the following is least useful to astronomers?
a) an ground-based optical telescope (i.e., one located on the surface of the Earth).
b) a ground-based X-ray telescope.
c) a ground-based radio telescope.
d) an optical telescope in space.
e) an X-ray telescope in space.

10. Which of the following spacecraft orbited Saturn?
a) Messenger.
b) Global Surveyor.
c) Cassini.
d) The Europa Orbiter.
e) Pathfinder.

11. Which moon in our solar system is closest in diameter to its planet?
a) Phobos.
b) Titan.
c) Charon.
d) The Moon.
e) Ganymede.

12. What is the name of Jupiter's largest moon?
a) Callisto.
b) Io.
c) Titan.
d) Europa.
e) Ganymede.

13. Ranking the known planets, dwarf planets, and moons in our solar system in order by size, from largest to smallest, Pluto is ranked:
a) Ninth.
b) Tenth.
c) Sixteenth.
d) Seventeenth.
e) Thirty-first.

14. Which of the following planets has only been visited by one spacecraft?
a) Mercury.
b) Saturn.
c) Uranus.
d) Neptune.
e) Answers c and d above.

15. What is the name of the rover operating on the surface of Mars right now?
a) Magellan.
b) Cassini.
c) Curiousity.
d) Viking.
e) Messenger.

16. How long is a sidereal day on Mercury?
a) 23 hours 56 minutes.
b) 24 hours.
c) 24 hours 37 minutes.
d) 58.7 days.
e) 249 years.

17. How many moons in the solar system are bigger than Pluto?
a) none.
b) one.
c) two.
d) seven.
e) thirty-nine.

18. How many moons does Mars have?
a) none.
b) 1.
c) 2.
d) 29.
e) 39.

19. Which of the following moons is orbiting around its planet in the reverse direction from most of the motions the solar system?
a) The Moon.
b) Callisto.
c) Ganymede.
d) Titan.
e) Triton.

20. Which of the following is the correct order of the densities of the different types of planets?
a) densest: terrestrial; next dense: Jovian; lowest density: Pluto.
b) densest: Jovian; next dense: Pluto; lowest density: terrestrial.
c) densest: terrestrial; next dense: Pluto; lowest density: Jovian.
d) densest: Jovian; next dense: Pluto; lowest density: terrestrial.
e) densest: Jovian; next dense: terrestrial; lowest density: Pluto.

21. The Very Large Array is a collection of 27 radio telescopes, each with a diameter of 25 meters, spread out in a Y-shaped array with a diameter of 22 miles in New Mexico. This telescope:
a) Has a light gathering power equal to that of a single 22 mile diameter telescope.
b) Has a resolution equal to that of a single 22 mile diameter telescope.
c) Has both a resolution and a light gathering power equal to that of a single 22 mile diameter telescope.
d) Has a resolution equal to that of a single 25 meter diameter telescope, but a light gathering power equal to that of a 22 mile diameter telescope.
e) Has a light gather power and a resolution equal to that of a single 25 meter diameter telescope.

22. How many spacecraft have visited Triton and its planet?
a) none.
b) one.
c) two.
d) four.
e) five.

23. Which of the following planets has the slowest spin rate?
a) The Earth.
b) Mars.
c) Venus.
d) Jupiter.
e) Saturn.

24. Which of the following planets has never been visited by a spacecraft?
a) Mercury.
b) Mercury, Uranus, Neptune, and Pluto.
c) Uranus, Neptune, and Pluto.
d) Pluto.
e) None of the above.

25. As an interstellar gas cloud gravitationally contracts in the process of forming into a star and planets:
a) its spin rate stays the same, as does its shape.
b) its spin rate stays the same, and it flattens to a disk.
c) its spin rate decreases, and it flattens to a disk.
d) its spin rate increases, and it flattens to a disk.
e) its spin rate increases, and it expands from a disk into a spherical shape.

26. Asteroids are probably:
a) pieces of a planet that broke up.
b) left-over planetesimals from the formation of the early solar system.
c) pieces of Jupiter that broke off.
d) the same composition as comets, but in the inner solar system rather than further out.
e) alien spacecraft.

27. Which of the following is a characteristic of terrestrial planets?
a) Densities of approximately 1 g/cm³.
b) Located in the outer solar system.
c) Diameter of 4 or more earth diameters.
d) Likely similar to Kuiper Belt Objects.
e) Mainly made of materials with high evaporation temperatures.

28. Which of the following best describes the rotation of Venus, compared to the rotation of Earth?
a) Much slower, and in a backwards direction.
b) Much faster, and in a backwards direction.
c) Much slower, in the same direction as Earth's.
d) Much faster, in the same direction as Earth's.
e) Tidally locked to the Sun, so that it spins once on its axis for each orbit around the Sun.

29. What is the sidereal day of Venus?
a) 243 days.
b) 23 hours 56 minutes.
c) 24 hours 37 minutes.
d) 17 hours.
e) 10 hours.

30. The density of water is 1 g/cm³, while the density of rock is 2-3 g/cm³. What is the average density of the Earth?
a) 0.1 g/cm³.
b) 0.7 g/cm³.
c) 1 g/cm³.
d) 2 g/cm³.
e) 5.5 g/cm³.

31. Which type of light can travel through the Earth's atmosphere without being absorbed very much?
a) X-rays and ultraviolet.
b) ultraviolet and X-rays.
c) visible, ultraviolet, and X-rays.
d) visible and radio.
e) visible, radio, and ultraviolet.

32. The Messenger spacecraft targeted:
a) Mercury.
b) Venus.
c) Mars.
d) Jupiter.
e) Pluto.

33. Io is a moon of which planet?
a) Mars.
b) Jupiter.
c) Saturn.
d) Neptune.
e) Pluto.

34. Which of the following does NOT happen when an interstellar cloud becomes a solar system?
a) the young star has a very strong stellar wind, which blows out left-over gas and dust.
b) the cloud flattens to a disk.
c) the spin rate of the cloud slows down as the cloud contracts.
d) the planets are semi-molten when they are first formed.
e) planetesimals collide to produce bigger objects.

35. An interferometer telescope is:
a) a telescope in space.
b) a telescope that uses a primary lens instead of a mirror.
c) a telescope that observes X-ray light.
d) a telescope that has both a secondary mirror and a tertiary mirror.
e) a collection of several telescopes working together.

36. How many moons in the solar system are larger than Mercury?
a) none.
b) 1.
c) 2.
d) 7.
e) 16.

37. When a planet or moon is completely enshrouded by clouds which visible light cannot penetrate, which of the following method or methods can be used to study the surface?
a) use X-rays.
b) use radar.
c) use gamma-rays.
d) send a spacecraft to land on its surface.
e) both b) and d) above.

38. Our best images of Neptune and its moons came from:
a) Pioneer 10.
b) Mariner 10.
c) Voyager 2.
d) Viking 2.
e) the Messenger spacecraft.

39. Which of the following is true about asteroids?
a) they are not usually found in the ecliptic.
b) they are chunks of about half ice and half rock.
c) they are probably left-over plantesimals from the formation of the solar system.
d) they are the same thing as comets, but are found in the inner part of the solar system while comets are found in the outer part.
e) they are pieces of a planet that broke apart during a collision with another planet.

40. Which of the following spacecraft visited all four Jovian planets?
a) Messenger.
b) Viking 2.
c) Voyager 2.
d) Galileo.
e) Cassini.

41. The spacecraft that landed successfully on Venus:
a) were all NASA spacecraft.
b) survived for only short amounts of time before failing, but sent back pictures.
c) unfortunately were not able to send back any pictures, so we have never seen the surface of Venus close-up.
d) spacecraft have orbited Venus, but none has landed successfully.
e) no spacecraft has visited Venus.

42. Which of the following moons orbits its planet in a backwards direction, compared to most of the motions in the solar system?
a) The Moon.
b) Io.
c) Europa.
d) Ganymede.
e) Triton.

43. The resolution of a 1 meter space telescope is:
a) twice that of a 0.5 meter space telescope.
b) half that of a 0.5 meter space telescope.
c) four times that of a 0.5 meter space telescope.
d) one quarter that of a 0.5 meter space telescope.
e) 16 times that of a 0.5 meter space telescope.

44. The ETSU radio telescope has a diameter of about 3 meters, similar in diameter to the Infrared Telescope Facility (IRTF) on Mauna Kea, in Hawaii, a telescope used for short-wavelength infrared observations, and the 3 meter optical telescope on the Canary Islands. The relative resolutions of these three telescopes are:
a) best: Canary Islands; next: IRTF; worst: ETSU radio telescope.
b) best: IRTF; next: Canary Islands: worst: ETSU radio telescope.
c) best: ETSU radio telescope; next: IRTF; worst: Canary Islands.
d) best: ETSU radio telescope; next: Canary Islands; worst: IRTF.
e) best: Canary Islands; next: ETSU radio telescope; worst: IRTF.

45. The resolution of a telescope:
a) increases (gets worse) with increasing wavelength of light.
b) increases with increasing diameter of primary mirror or lens.
c) increases with decreasing wavelength of light.
d) increases with decreasing diameter of primary mirror or lens.
e) both a) and d) above.

46. Audible sound has wavelengths of approximately 1 meter, while visible light has wavelengths of about 5 X 10^-7 meters. Therefore:
a) Sound travels much faster than light.
b) With a door about a meter in size, diffraction is much more significant for audible waves than visible waves.
c) Light never bends around corners, but sound does.
d) Light does not travel through a vacuum, but sound can.
e) Light and sound are exactly the same thing, except they have different frequencies and wavelengths.

47. The reason that you can hear but not see a person standing outside the classroom door is:
a) Sound waves are much shorter than visible light waves, and so travel farther.
b) Sound waves are longer than visible light waves, and so bend more when they go through a doorway.
c) Light never bends around corners, but sound does.
d) Sound travels faster than light.
e) Light does not travel through a vacuum.

48. Asteroids:
a) Mostly orbit the Sun out of the plane of the ecliptic.
b) Are likely pieces of a planet that broke apart during a collision with another planet.
c) Are likely left-over planetesimals.
d) Mostly orbit the Sun between the orbits of Earth and Mars.
e) Are extremely young objects, compared to the age of the rocks on the surface of the Earth.

49. Eris is:
a) A dwarf planet.
b) A Galilean Moon.
c) A moon of Mars.
d) A planet orbiting alpha Centaurus.
e) A small moon of Pluto.

50. Which planet orbits the Sun in a direction opposite that of the rest of the planets?
a) Mercury.
b) Venus.
c) Saturn.
d) Neptune.
e) None.

51. How many moons are larger than Mercury?
a) 0.
b) 1.
c) 2.
d) 7.
e) 22.

52. The diffraction of light is:
a) the bending of light when it passes from one medium to another.
b) the bending of light waves around corners.
c) the reflection of light waves.
d) the minimum separation between two stars in the sky where an observer can just distinguish two independent stars.
e) thermal radiation.

53. What type of light travels easily through our atmosphere, so ground-based astronomy is possible at these wavelengths?
a) Only visible.
b) Visible, UV, and X-rays.
c) Visible and radio.
d) Gamma rays, X-rays, and visible.
e) All types.

54. According to the recent IAU definition, which of the following is a dwarf planet?
a) Titan.
b) Mercury.
c) the asteroids.
d) Eris.
e) Europa.

55. Which of the following objects has the smallest diameter?
a) Ganymede
b) The Moon
c) Europa
d) Pluto
e) Triton

56. Which spacecraft has visited Neptune?
a) Pioneer 10, Pioneer 11, Voyager 1, and Voyager 2.
b) 23 spacecraft, about half from the U.S., half from the Soviet Union, and one from the European space agency.
c) Just Mariner 10.
d) Just Voyager 2.
e) None.

57. Which spacecraft orbited Mercury?
a) Viking.
b) Messenger.
c) Cassini.
d) New Horizon
e) None.

58. Which of the following objects is larger than Pluto?
a) The Earth's Moon.
b) Ganymede.
c) Europa.
d) Triton.
e) All of the above.

59. The angular momentum of a spinning object with mass M, spin velocity V, and radius R is proportional to:
a) MV/R.
b) MV²/R.
c) M/(VR).
d) M²V³R⁴.
e) MVR.

60. Comets:
a) Mostly orbit the Sun out of the plane of the ecliptic.
b) Are likely pieces of planets that broke apart during collision with other planets.
c) Are rocky objects.
d) Mostly orbit the Sun between the orbits of Earth and Mars.
e) Are extremely young objects, compared to the age of the rocks on the surface of the Earth.

61. Which planet has the longest sidereal day?
a) Mars.
b) Venus.
c) Saturn.
d) Jupiter.
e) Earth.

62. Triton:
a) Is the largest moon in the solar system.
b) Is a moon of Saturn.
c) Is considered a dwarf planet, according to the new IAU definition.
d) Orbits its planet in an opposite direction compared to the other moons in the solar system.
e) All of the above.

63. Which of the following is not a Galilean Moon?
a) Callisto.
b) Europa.
c) Io.
d) Ganymede.
e) Titan.

64. Which planet is tipped over on its side, relative to the spin axes of the other planets?
a) Mercury.
b) Saturn.
c) Mars.
d) Jupiter.
e) Uranus.

65. The Kuiper Belt is:
a) the group of asteroids orbiting the Sun between the orbits of Mars and Jupiter.
b) the many small moons that orbit Jupiter.
c) a collection of icy/rocky objects orbiting the Sun out beyond the orbit of Neptune.
d) the rings of Saturn.
e) a group of small asteroids that orbit Mars.

66. The Very Large Array is a group of 25-meter radio telescopes spread over an area with a diameter of 22 miles in New Mexico that all work together. Together, they have:
a) The resolution of a single 22 mile telescope.
b) The light gathering power of a single 22 mile telescope.
c) Both the resolution and the light gathering power of a single 22 mile telescope.
d) Both the resolution and the light gathering power of a single 25-meter telescope.
e) The resolution of a single 25 X 22 = 550 mile telescope.

67. Refraction of light is caused by:
a) atoms being ionized.
b) atoms being excited.
c) a relative motion of the source of light and the observer.
d) the speed of light always being a constant, no matter what kind of material the light is moving through.
e) the speed of light changing when light travels from one medium into another.

68. What do astronomers call a telescope that uses a primary lens instead of a primary mirror?
a) A refracting telescope.
b) A Newtonian Focus telescope.
c) A Coude Focus telescope.
d) A Cassegrain Focus telescope.
e) A Prime Focus telescope.

69. Which of the following statements about the speed of light is correct?
a) the shorter the wavelength of light, the faster the speed, in a vacuum.
b) the longer the wavelength, the faster the speed, in a vacuum.
c) all wavelengths of light travel at the same speed in a vacuum, but not in other substances.
d) all wavelengths of light travel at the same speed, both in a vacuum and in all other substances.
e) light travels instantaneously.

70. For which kind of telescope does red light focuses at a different location than blue light?
a) A Newtonian telescope.
b) A Prime Focus telescope.
c) A refracting telescope.
d) A Cassegrain focus telescope.
e) For all kinds of telescopes.

71. What do astronomers call a telescope which has three mirrors, a primary, a secondary, and a tertiary, which are set so that the light rays are deflected to the same location no matter where in the sky the telescope is pointed?
a) A Newtonian telescope.
b) A Prime Focus telescope.
c) A refracting telescope.
d) A Cassegrain focus telescope.
e) A Coude Focus telescope.

72. The speed of light is:
a) a constant for all wavelengths, whether in vacuum, glass, air, or water.
b) a constant for all wavelengths in a vacuum, but it slows down in glass, air, or water.
c) a constant for all wavelengths in a vacuum, but it speeds up in glass, air, or water.
d) in a vacuum, shorter wavelength light travels faster than longer wavelength light.
e) in a vacuum, longer wavelength light travels faster than shorter wavelength light.

73. Comets:
a) Mostly orbit the Sun in the plane of the ecliptic.
b) Mostly orbit the Sun between the orbits of Earth and Mars.
c) Are balls of mostly metal.
d) Are rocky objects.
e) Are made up of ice plus rock.

74. How much bigger is the light gathering power of the 5 meter Palomar telescope, compared to a 1 meter telescope?
a) five times larger.
b) twenty-five times larger.
c) 1/5 as large.
d) 1/25th as large.
e) the same.

75. Which of the following is a Galilean Moon?
a) Callisto.
b) Triton.
c) Phobos.
d) Titan.
e) The Moon.

76. As a spinning interstellar cloud gravitationally collapses to form a solar system, what happens to its spin rate?
a) it gradually slows down.
b) it stops spinning.
c) it speeds up.
d) it keeps spinning at the same rate.
e) it depends upon its mass; a high mass cloud slows down, while a low mass cloud spins up.

77. According to the recent IAU definition, a dwarf planet is:
a) an object larger than Pluto, but that orbits a planet rather than the Sun.
b) an asteroid.
c) a spherical object that orbits the Sun, but that has not cleared the neighborhood around its orbit.
d) a non-spherical object that orbits the Sun.
e) a terrestrial planet, like Mercury, Earth, Venus, or Mars.

78. Which planet is spinning backwards, compared to the other planets?
a) Mercury.
b) Venus.
c) Mars.
d) Jupiter.
e) Saturn.

79. What do astronomers call a collection of telescopes that all act together, and so provide much better spatial resolution than each individual telescope alone?
a) a gathering telescope.
b) a diffraction telescope.
c) an interferometer.
d) an extramirror telescope.
e) a Galilean telescope.

80. Ganymede:
a) Is bigger than Mercury.
b) Is bigger than Pluto, but smaller than Mercury.
c) Is bigger than Mars.
d) Is slightly smaller than the Earth's Moon.
e) Is the smallest of the Galilean Moons.

81. Ceres:
a) Is a dwarf planet, according to the recent IAU definition.
b) Is an asteroid.
c) Is approximately spherical.
d) Orbits the Sun, rather than a planet.
e) All of the above.

82. The most recent spacecraft to Mercury is:
a) Voyager 1.
b) Voyager 2.
c) Galileo.
d) Cassini.
e) Messenger.

83. The density of Pluto is:
a) Larger than that of any of the eight major planets.
b) Less than any of the eight major planets.
c) Larger than that of rocks alone, meaning it contains a lot of metals as well.
d) Between that of ice and that of rock, suggesting it contains both rock and ice.
e) Unknown.

84. In an X-ray telescope, to reflect the X-rays and bring them to a focus:
a) The light must hit the mirror nearly head-on.
b) The light must hit the mirror at a very large angle, relative to the normal.
c) X-rays can never be reflected; they are too high energy.
d) No X-ray telescopes exist yet; we do not yet have the technology to build one.
e) There is no point in building an X-ray telescope, since no astronomical objects produce that high energy light.

85. Voyager 2 visited:
a) Jupiter.
b) Saturn.
c) Uranus.
d) Neptune.
e) All of the above.

86. The density of water is 1 g/cm³, while the density of rock is 2-3 g/cm³, and metals have densities of about 8 - 10 g/cm³. What is the average density of the Earth?
a) 0.7 g/cm³.
b) 1.0 g/cm³.
c) 2.0 g/cm³.
d) 5.5 g/cm³.
e) 15 g/cm³.

87. As inferred from their densities, which of the following have overall compositions which are roughly half rock and half ice?
a) The terrestrial planets.
b) The Moon.
c) The asteroids.
d) Pluto.
e) All of the above.

88. Titan:
a) Is the largest moon of Jupiter.
b) Is bigger than Pluto but smaller than Mercury.
c) Is the closest of the Galilean moons to Jupiter.
d) Orbits Jupiter in a different direction from the rest of Jupiter's moons.
e) Has a diameter larger than that of Mercury.

89. Which of the following is classified as both a dwarf planet, AND as an asteroid, and orbits the Sun in the asteroid belt?
a) Io.
b) Charon.
c) Ceres.
d) Titan.
e) All of the above.

90. How much bigger is the light gathering power of the 8 meter Keck telescope, compared to the 1 meter SARA telescope?
a) 8 times larger.
b) 8² = 64 times larger.
c) 8³ = 512 times larger.
d) 1/8th as large.
e) the same.

91. The primary target of the spacecraft named New Horizons was:
a) Mercury.
b) Venus.
c) Mars.
d) The Sun.
e) Pluto.

92. Which of the following objects has the highest density?
a) Jupiter.
b) Saturn.
c) Earth.
d) Pluto.
e) Callisto.

93. The bending of waves around corners when the waves go through a door is called:
a) Diffraction.
b) Refraction.
c) Ionization.
d) Differentiation.
e) Excitation.

94. What is unusual about the design of the Chandra X-ray telescope, compared to an optical telescope such as those at the ETSU observatory?
a) It is a Cassegrain focus telescope.
b) The light rays hit the mirror at a very large angle, relative to the normal line.
c) It contains 27 telescopes spread out over a distance of 22 miles.
d) It is built into a natural valley in Puerto Rico.
e) It is located on the top of a tall mountain in Hawaii.

95. Triton:
a) Is the largest moon of Jupiter.
b) Is bigger than Mercury.
c) Is the closest of the Galilean moons to Jupiter.
d) Orbits Neptune in a different direction than most of the moons in the solar system.
e) Has a diameter larger than that of Mars.

96. Which of the following planets only has two known moons?
a) Uranus.
b) Mercury.
c) Mars.
d) Pluto.
e) Neptune.

97. Phobos is:
a) One of the Galilean Moons.
b) The largest moon of Neptune.
c) A moon of Mars.
d) The largest moon of Pluto.
e) One of the smaller moons of Pluto.

98. Most radio telescopes have the detector/receiver placed in front of the primary mirror/dish. This telescope design is called a:
a) Prime focus telescope.
b) Coude focus telescope.
c) Newtonian telescope.
d) Cassegrain telescope.
e) Refracting telescope.

99. Which of the following is NOT true about comets?
a) comets generally do not orbit the Sun in the ecliptic.
b) comets have lower densities than asteroids.
c) comets are generally further out in the solar system than asteroids.
d) comets tend to have more elongated orbits than asteroids.
e) most comets in our solar system orbit the Sun between Mars and Jupiter.

100. Which of the following planets has a sidereal day similar to that of Earth, and a tilt to its axis that is similar to that of Earth?
a) Mars.
b) Venus.
c) Uranus.
d) Pluto.
e) Mercury.

101. Which type of light diffracts the most going through an opening a meter in diameter?
a) Visible Light.
b) Ultraviolet.
c) Infrared.
d) Gamma Rays.
e) Radio waves.

102. Which of the following is NOT true about asteroids?
a) asteroids generally orbit the Sun near the plane of the ecliptic.
b) asteroids are likely left-over planetesimals.
c) asteroids are generally closer to the Sun than comets.
d) asteroids tend to have rounder orbits than comets.
e) asteroids are made up of mostly ice.

103. The telescopes used during the ETSU Astronomy I labs are Cassegrain focus telescopes. In this telescope design, the focus is:
a) in back of the primary mirror, behind a hole in the mirror through which the light is reflected by a secondary mirror.
b) off the side of the mirror, where the light has been reflected by a secondary mirror.
c) in a permanent location which does not move, where the light is directed using the primary mirror, a secondary mirror, and a tertiary mirror.
d) right in front of the primary mirror at the focus; there is no secondary mirror.
e) behind a primary lens.

104. In a period of an hour, a 10 meter telescope gathers how many more photons than a 1 meter telescope does in the same amount of time?

a) ten times as many.
b) 10 X 10 = 100 times as many.
c) 10³ = 1000 times as many.
d) 10⁴ = 10,000 times as many.
e) they gather the same number of photons.

105. From largest to smallest in terms of the diameter of the planet, what is the order of the terrestrial planets?
a) Mercury, Venus, Earth, Mars.
b) Venus, Earth, Mercury, Mars.
c) Earth, Venus, Mercury, Mars.
d) Earth, Venus, Mars, Mercury.
e) Venus, Earth, Mars, Mercury.

106. Titan:
a) Is the largest moon in the solar system.
b) Is one of the Galilean Moons of Jupiter.
c) Orbits its planet backwards, compared to most of the other moons in the solar system.
d) Is larger than Mars.
e) Is the largest moon of Saturn.

107. Callisto:
a) Is the largest asteroid in the asteroid belt.
b) Is one of the moons of Mars.
c) Is the largest moon of Pluto.
d) Is the outermost of the Galilean Moons of Jupiter.
e) Is a moon of Mercury.

108. There are seven moons in our solar system that are:
a) Bigger than Mercury.
b) Bigger than Mars.
c) Bigger than Pluto.
d) Bigger than Venus.
e) Bigger than the Earth's Moon.

109. Curiousity and Opportunity are:
a) The names of the two spacecraft which have visited Mercury.
b) The names of the two rovers that operated on Mars.
c) The names of the first two spacecraft to orbit Venus.
d) The names of the first two spacecraft to visit Jupiter and Saturn.
e) The names of the first two spacecraft to flyby Uranus and Neptune.

110. Io:
a) Is the largest moon in the solar system.
b) Has a diameter bigger than Mercury and Pluto.
c) Is the closest of the Galilean Moons to Jupiter.
d) Orbits its planet backwards, compared to most of the other moons in the solar system.
e) Is larger than Mars.

111. Which of the following is true about radio telescopes operating at a wavelength of 0.5 meters?
a) They must be placed above the atmosphere of the Earth.
b) Most radio telescopes use a Coude Focus design.
c) To reflect, the photons must hit the mirrors at a large angle relative to the normal line.
d) The mirrors can be made out of chicken wire.
e) Radio waves never reflect from a mirror.

112. Which of the following is true about Kuiper Belt Objects?
a) They mostly orbit the Sun between the orbit of Mars and the orbit of Jupiter.
b) They mostly orbit the Sun between the orbit of the Earth and the orbit of Mars.
c) They are made up of nearly all rock.
d) They are made up of nearly all metal, with some rock.
e) They orbit the Sun outside the orbit of Uranus.

113. In a Newtonian Design telescope, the focus is:
a) in back of the primary mirror, behind a hole in the mirror through which the light is reflected by a secondary mirror.
b) off the side of the primary mirror, where the light has been reflected by a flat secondary mirror.
c) in a permanent location which does not move, where the light is directed using the primary mirror, a secondary mirror, and a tertiary mirror.
d) right in front of the primary mirror at the focus; there is no secondary mirror.
e) behind a primary lens.

114. Pluto is:
a) tidally locked to Charon.
b) bigger than Io and Europa.
c) classified as a terrestrial planet.
d) bigger than the Earth's moon.
e) mostly metals, with a little bit of rock.

115. The orbital angular momentum of a planet orbiting the Sun depends upon the planet's mass M, the planet's orbital velocity V, and the distance of the planet from the Sun R. The orbital angular momentum is proportional to:
a) M x V x R.
b) M/(V x R).
c) (M x V)/R.
d) (M X R)/V.
e) (V X R)/M.

116. Which of the following moons belongs to Neptune?
a) Triton.
b) Callisto.
c) Ganymede.
d) Titan.
e) Deimos.

117. How many spacecraft have visited Mercury so far?
a) Forty-three.
b) 23.
c) One.
d) Two.
e) Zero.

118. Which of the following planets has only two known moons?
a) Pluto.
b) Uranus.
c) Mars.
d) Neptune.
e) Mercury.

119. Saturn's largest moon is:
a) Ganymede.
b) Triton.
c) Eris.
d) Titan.
e) Phobos.

120. Voyager 2 visited both Uranus and Neptune. Why didn't Voyager 1?
a) It accidently crash-landed on Saturn.
b) It exploded on the launch pad, and never made it into space.
c) It left the plane of the eliptic because of a close passage by Titan.
d) It went into the inner solar system, to visit Venus and Mercury.
e) It was intentionally crash-landed on Jupiter.

121. The NASA Chandra Telescope was the largest satellite ever launched into space by the Space Shuttle. It is large because of the very large distance between the mirrors and the focal point. What kind of telescope is it?
a) Ultraviolet telescope.
b) Infrared telescope.
c) Visible light telescope.
d) Radio telescope.
e) X-ray telescope.

122. Which of the following objects is classified as a dwarf planet?
a) Ganymede.
b) Mercury.
c) Phobos.
d) Titan.
e) Ceres.

123. Venus:
a) Has never had a spacecraft land on its surface.
b) Is orbiting the Sun in a direction opposite from the other planets.
c) Has a sidereal day of only 10 hours long.
d) Is classified as a dwarf planet.
e) Has no moons.

124. Assuming operations at the same wavelength, the angular resolution (in arcseconds) of a 3 meter space telescope is:
a) three times that of a 1 meter space telescope
b) nine times that of a 1 meter space telescope.
c) 1/3 that of a 1 meter space telescope.
d) 1/9th that of a 1 meter space telescope.
e) 1/3⁴ = 1/81 times that of a 1 meter space telescope.

125. The asteroids in the asteroid belt are thought to be:
a) Small moons of Jupiter that escaped from Jupiter's gravitational field.
b) Pieces of a planet that broke apart in a collision.
c) Left-over planetesimals from the inner solar system that never formed into a planet.
d) Left-over planetesimals that formed in the outer solar system, beyond Neptune, and then wandered into the inner solar system.
e) The nuclei of comets that formed in the Oort Cloud and then were deflected by Jupiter's gravitational field.

126. In a period of an hour, a 5 meter telescope gathers how many more photons than a 1 meter telescope does in the same amount of time?

a) five times as many.
b) 10 times as many.
c) 25 times as many.
d) 75 times as many.
e) they gather the same number of photons.

127. Which is the correct order of the following objects, in terms of diameter, from SMALLEST to LARGEST?

a) Pluto, Titan, Ganymede, Mercury.
b) Pluto, Titan, Mercury, Ganymede.
c) Pluto, Mercury, Ganymede, Titan.
d) Pluto, Mercury, Titan, Ganymede.
e) Titan, Ganymede, Pluto, Mercury.

128. Uranus:
a) Has four moons larger than Pluto.
b) is tipped over on its side, relative to the spin axes of the other planets (i.e., it has a very large tilt to its spin axis compared to the other planets).
c) Has a density greater than the density of rock, thus it contains mostly rock and metal.
d) Orbits the Sun in a direction opposite that of the rest of the planets.
e) Has no known moons.

129. Ganymede is:
a) A dwarf planet.
b) A moon of Saturn.
c) The closest moon to Jupiter.
d) About half the diameter of Pluto.
e) The largest moon in the solar system.

Answers: 1c, 2d, 3c, 4c, 5d, 6e, 7b, 8b, 9b, 10c, 11c, 12e, 13d, 14e, 15c, 16d, 17d, 18c, 19e, 20c, 21b, 22b, 23c, 24e, 25d, 26b, 27e, 28a, 29a, 30e, 31d, 32a, 33b, 34c, 35e, 36c, 37e, 38c, 39c, 40c, 41b, 42e, 43b, 44a, 45e, 46b, 47b, 48c, 49a, 50e, 51c, 52b, 53c, 54d, 55d, 56d, 57b, 58e, 59e, 60a, 61b, 62d, 63e, 64e, 65c, 66a, 67e, 68a, 69c, 70c, 71e, 72b, 73e, 74b, 75a, 76c, 77c, 78b, 79c, 80a, 81e, 82e, 83d, 84b, 85e, 86d, 87d, 88e, 89c, 90b, 91e, 92c, 93a, 94b, 95d, 96c, 97c, 98a, 99e, 100a, 101e, 102e, 103a, 104b, 105d, 106e, 107d, 108c, 109b, 110c, 111d, 112e, 113b, 114a, 115a, 116a, 117d, 118c, 119d, 120c, 121e, 122e, 123e, 124c, 125c, 126c, 127d, 128b, 129e.