Astronomy Related Multiple Choice Questions With Answers

Astronomy Questions Answers Part 4 Eduhyme

Suppose that you live in South Carolina. Imagine that you go to bed, and in the morning, you awaken in Australia, and do no know that you have been transported to a location south of the equator. It is clear morning. The sun appears to rise normally enough, but after a while you notice something strange. Rather than progressing generally south and west, as the sun always does during the early morning hours in the northern hemisphere, the sun moves north and west.

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.

Also Read:

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. The average time interval between major comet impacts on the Earth is esti¬mated to be on the order of several

(a) decades.
(b) Centuries.
(c) Tens of millennia.
(d) Tens of millions of years.
(e) Tens of billions of years.

2. Orbital resonances can be caused by

(a) Solar flares and sunspots.
(b) Synchronization of a planet’s rotation rate with the rotation rate of the Sun.
(c) Mutual gravitation between different moons of the same planet.
(d) Powerful magnetic fields, such as the magnetosphere of Jupiter.
(e) radio-wave emissions from planets.

3. The “probability fallacy” refers to

(a) An overestimate of the chance that something will happen.
(b) An inaccurate estimate of the chance that something took place.
(c) Inappropriate use of statistics.
(d) A statement of belief rather than an estimate of probability.
(e) The derivation of a theory based on faulty observation.

4. According to one theory, tektites come from

(a) The Sun.
(b) The Moon and Mars.
(c) The planet Mercury.
(d) Comets.
(e) Beyond the Milky Way galaxy.

5. A mutation is

(a) An eccentricity in a planet’s orbit.
(b) The formation of a planet from cosmic dust and rocks.
(c) A star that has been modified by a collision with another star.
(d) A change in the shape of a crater.
(e) None of the above.

6. On the surface of an outer-planetary moon, craters can last a long time even when the chemical composition is largely frozen water. This is so because

(a) Water periodically boils up from the interior, freezing on the surface.
(b) Tidal interactions with the parent planet heat the moon from within.
(c) The extremely low temperatures make the ice as hard as granite.
(d) The moon’s atmosphere prevents wind erosion.
(e) No! Craters on the surfaces of an outer-planetary moon do not last long.

7. A Sun grazer is

(a) An asteroid that falls into the Sun.
(b) A star that passes so close to the Sun that the two stars pull matter from each other.
(c) A comet that enters the solar corona at perihelion.
(d) A comet that passes directly between Earth and the Sun.
(e) A comet that passes directly behind the Sun as seen from Earth.

8. In order for an astronaut to travel to the other side of the Milky Way galaxy within the span of his or her lifetime,

(a) The space ship would have to be well streamlined.
(b) The space ship would have to use liquid fuel.
(c) The space ship would have to travel at almost the speed of light.
(d) The space ship would have to travel faster than the speed of light.
(e) No! No astronaut can possibly reach the other side of the Milky Way galaxy within the span of his or her human lifetime no matter how fast the space ship goes.

9. Project Ozma involved the use of

(a) The Hubble Space Telescope.
(b) Unmanned space probes.
(c) time-exposure photography.
(d) Radio telescopes.
(e) Manned space flights.

10. Suppose that there are two celestial objects, X and Y. Object X has a visual magnitude of 2, and object Y has a visual magnitude of 3. Which of the following statements is true?

(a) Object X is 2.5 times as bright as object Y.
(b) Object Y is 2.5 times as bright as object X.
(c) Both objects are too dim to be seen without the aid of a telescope.
(d) Both objects are the same brightness, but they are of different colors.
(e) None of the statements is true.

11. According to the tidal theory of the formation of the Solar System,

(a) The planets formed from matter that two passing stars pulled from each other.
(b) The planets condensed from a disk of matter in orbit around the Sun.
(c) The planets formed from tidal interactions among gas and dust clouds.
(d) Two stars collided directly, and the debris condensed into planets.
(e) The planets were captured by the Sun’s gravity from interstellar space.

12. One of the major moons of the outer planets is believed by some astronomers to have once been a planet itself that came too close to the larger planet and became a natural satellite. This moon is

(a) Io.
(b) Rhea.
(c) Triton.
(d) Ariel.
(e) Miranda.

13. The “dirty snowball” portion of a comet is called the

(a) Little ton portion.
(b) Whipple portion.
(c) Nucleus.
(d) Coma.
(e) Tail.

14. Some ancient astronomers talked about “music of the spheres.” Today we believe that the phenomenon they described was

(a) A figment of their imaginations.
(b) Caused by solar radiation.
(c) Caused by Earth’s tidal interactions with the Moon.
(d) Caused by tidal interactions among Earth, the Moon, and the Sun.
(e) Noise produced by falling meteors.

15. The term “shooting star” refers to

(a) A visible meteor.
(b) A solar flare.
(c) Meteoric dust.
(d) An asteroid.
(e) A planetary moon.

16. Ganymede is a moon of

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

17. Titan, one of the moons of Saturn, has been suggested as

(a) A place where life must exist.
(b) A place with an Earthlike environment.
(c) The place with the most violent storms in the Solar System.
(d) A generator of powerful radio waves.
(e) A place where future interplanetary travelers ought to go.

18. The major moons of Uranus

(a) are all believed to be comets that were captured by Uranus’s gravitation.
(b) Orbit in the same plane as Uranus orbits the Sun.
(c) Have highly eccentric orbits.
(d) Orbit almost directly over the planet’s poles.
(e) Orbit in the same plane as the planet’s equator.

19. The Oort cloud is notable because it is a source of

(a) Radiation.
(b) Radio signals.
(c) Infrared energy,
(d) Fuel for the Sun.
(e) None of the above.

20. Which of the following statements is false?

(a) Each planet follows an elliptical orbit around the Sun, with the Sun at one focus of the ellipse.
(b) An imaginary line connecting any planet with the Sun sweeps out equal areas in equal periods of time.
(c) For each planet, the square of its sidereal period is directly proportional to the cube of its average distance from the Sun.
(d) In reality, no planet orbits in a perfect circle around the Sun; the orbits are always at least a little bit oblong.
(e) All the planets and all the planetary moons orbit in the same plane around the Sun.

21. The main sequence on the Hertz sprung-Russell diagram is

(a) Where the red giants are found.
(b) Where the white dwarfs are found.
(c) Where the Sun is found.
(d) Where stars are before hydrogen fusion begins.
(e) Where stars end up after they have burned out.

22. Stars seem to twinkle when observed from Earth’s surface because

(a) Dispersion of the starlight occurs in outer space.
(b) Turbulence in Earth’s atmosphere refracts the starlight.
(c) The stars actually are changing in brilliance.
(d) The solar wind refracts the starlight.
(e) The geomagnetic field bends the starlight.

23. If a neutron star is massive enough so that gravitation overpowers all other forces during the final collapse, the object will in theory become

(a) A black dwarf.
(b) A supernova.
(c) A white dwarf.
(d) An event horizon.
(e) A space-time singularity.

24. When Michelson and Morley measured the speed of light in various directions, they discovered that

(a) The speed of light is slowest in the direction in which Earth travels through space.
(b) The speed of light is fastest in the direction in which Earth travels through space.
(c) Earth drags the aluminiferous ether along with itself.
(d) The speed of light is the same in all directions.
(e) The speed of light cannot be accurately determined.

25. A black dwarf is

(a) A small planet with low albedo.
(b) A star in the process of formation, still dark because nuclear fusion has not yet begun.
(c) Any small, dark object in the Cosmos.
(d) An object whose gravitation is so intense that not even light can escape.
(e) A white dwarf that has burned out and cooled down.

26. Near the plane of our own Milky Way’s spiral disk, it is almost impossible to see distant galaxies and quasars because

(a) They are too far away.
(b) The gas and dust in the plane of the Milky Way obscure the view.
(c) There are few distant objects in the plane of the Milky Way.
(d) The gravitation of the Milky Way bends light from such objects away from us.
(e) No! It is easier to see distant objects near the plane of the Milky Way than in other regions of space.

27. Suppose that a space ship whizzes by so fast that clocks on board seem, as seen from our point of view, to be running at half speed. If the rest mass of the ship is 50 metric tons, what will be the mass of the ship from our point of view as it whizzes by?

(a) 25 metric tons
(b) 50 metric tons
(c) 100 metric tons
(d) 400 metric tons
(e) It cannot be determined without more information.

28. Gravitational waves

(a) Are like ripples in space and time.
(b) Cannot penetrate solid objects.
(c) Have been proven to be a theoretical fiction and not to exist in reality.
(d) Cause black holes to form.
(e) Travel faster than light.

29. Einstein’s principle of equivalence states that

(a) Gravitational force is just like acceleration force.
(b) Force equals mass times acceleration.
(c) The speed of light is constant no matter what.
(d) The speed of light is the highest possible speed.
(e) The shortest distance between two points is a straight line.

30. The term near IR refers to

(a) Energy at wavelengths slightly longer than visible red light.
(b) Energy at wavelengths slightly shorter than visible red light.
(c) Energy at wavelengths slightly longer than visible violet light.
(d) Energy at wavelengths slightly shorter than visible violet light.
(e) Energy from objects comparatively near the Solar System.

31. Regardless of whether a reference frame is accelerating or not, light rays always

(a) Travel in straight lines.
(b) Follow the shortest possible path between two points in space.
(c) Travel in curved paths.
(d) Are repelled by gravitational fields.
(e) Travel fastest in the direction of motion.

32. The distances to galaxies closer than about 10 million light years can be inferred by observing

(a) Cepheid variables in the galaxies.
(b) The extent to which the galaxies are tilted as we view them.
(c) The extent to which the spectra of the galaxies are blue-shifted.
(d) The waveforms of the pulses emitted by the galactic nuclei.
(e) The intensity of x-rays emitted by the spiral arms of the galaxies.

33. A teaspoonful of neutrons packed tightly together

(a) Would mass many thousands of kilograms.
(b) Would fly apart because like charges repel.
(c) Would instantly disintegrate.
(d) Would mass about the same as a teaspoonful of electrons.
(e) Would undergo nuclear fusion.

34. Fill in the blank in the following sentence: ‘According to astronomer Thomas Gold, the magnetic field in the immediate vicinity of a pulsar can be

(a) As intense as the field at Earth’s surface
(b) Perfectly uniform
(c) Trillions of times as intense as the field at Earth’s surface
(d) doughnut-shaped
(e) As weak as a trillionth of the intensity of the field at Earth’s surface

35. No quasar has ever been observed that has blue-shifted spectral lines. This lends support to the theory that

(a) Quasars are objects that have been ejected from our galaxy.
(b) Quasars are objects in the Solar System.
(c) Quasars have weak gravitational fields.
(d) Quasars are distant and are receding from us.
(e) No! There are plenty of quasars with blue-shifted spectra.

36. One minute of arc is equal to

(a) The distance light travels in 1 minute.
(b) 1/60 of an angular degree.
(c) 1/60 of a full circle.
(d) the angular distance the Sun travels across the sky in 1 minute.
(e) 1/60 of 1 hour of right ascension.

37. When astronomers scrutinized the so-called spiral nebulae, it was eventually discovered that they are

(a) Rotating clouds of gas and dust in the Milky Way.
(b) Black holes sucking in interstellar gas.
(c) Exploding stars.
(d) Distant congregations of stars outside the Milky Way.
(e) A mystery to this day; no one yet knows what they are.

38. The “ticks” emitted by a pulsar

(a) Occur at irregular and unpredictable intervals.
(b) Occur fastest when the pulsar is high in the sky and slowest when the pul¬sar is low in the sky.
(c) Occur fastest when the pulsar is low in the sky and slowest when the pul¬sar is high in the sky.
(d) Generally have rough waveforms, unlike the signals from radio transmitters.
(e) Have regular waveforms, just like the signals from radio transmitters.

39. A hypothetical point where matter enters our Universe from another space-time continuum is sometimes called

(a) a quasar.
(b) A white hole.
(c) A black hole.
(d) An event horizon.
(e) A pulsar.

40. Most astronomers believe the Sun will explode as a supernova

(a) 1 million to 2 million years from now.
(b) 500 million to 1 billion years from now.
(c) 1 billion to 2 billion years from now.
(d) 5 billion to 15 billion years from now.
(e) Never.

41. If a space ship from Earth landed on a planet made of antimatter,

(a) The space ship would sink to the center of the planet.
(b) The space ship would land normally, but no passengers could get off with¬out being annihilated.
(c) There would be a terrific explosion.
(d) It would be just the same as if the planet were made of matter.
(e) No! The ship could never land because it would be repelled by the anti¬matter planet.

42. Relativistic spatial distortion occurs

(a) Only at speeds faster than the speed of light.
(b) Only when objects accelerate.
(c) Only along the axis of relative motion.
(d) Only for extremely dense or massive objects.
(e) Only within black holes.

43. A spectroscope is used for

(a) Enhancing the quality of images seen through a telescope.
(b) Evaluating electromagnetic signals received at radio wavelengths.
(c) Transmitting signals in the hope of contacting extraterrestrial beings.
(d) Scrutinizing visible light by breaking it down by wavelength.
(e) Measuring the parallax of stars.

44. Imagine that a space ship whizzes by so fast that clocks on board seem, as seen from our point of view on Earth, to be running at one-third their normal speed. Suppose that you mass 60 kg on Earth and have a friend riding on the ship who also masses 60 kg on Earth. If your friend measures his mass while traveling on the ship, what will he observe it to be?

(a) 20 kg
(b) 60 kg
(c) 180 kg
(d) 540 kg
(e) It cannot be determined without more information.

45. Planetary Nebulae

(a) Form around massive planets.
(b) Are clouds of gas and dust from which planets form.
(c) Are gas and dust attracted by the gravitational fields of planets.
(d) Have stars at their centers.
(e) Are irregular in shape.

46. Spatial distortion can be caused by all the following except

(a) Acceleration.
(b) Gravitation.
(c) High relative speed.
(d) Black holes.
(e) The solar wind.

47. The gravitational radius of an object

(a) is directly proportional to its mass.
(b) is inversely proportional to its mass.
(c) is directly proportional to the square of its mass.
(d) is inversely proportional to the square of its mass.
(e) Does not depend on its mass.

48. When we look at a quasar that is 8 billion light-years away, we see

(a) The quasar as it appears right now.
(b) The quasar as it will appear 8 billion years in the future.
(c) The quasar as it appeared before the Solar System existed.
(d) An image that has traveled all the way around the known Universe.
(e) An illusion because astronomers doubt that anything exists that is 8 billion light-years distant.

49. The heliopause is

(a) The region in space where the solar wind gives way to the general circulation of interstellar gas and dust.
(b) The region in the Sun’s corona beyond which the temperature begins to drop.
(c) The region inside the Sun where radiation gives way to the convection.
(d) The time in the future at which the Sun’s hydrogen fuel will be all used up.
(e) The time in the future at which the Sun’s nuclear fusion reactions will all cease.

50. Time travel into the future might be possible by taking advantage of

(a) Relativistic time dilation.
(b) Relativistic mass distortion.
(c) Relativistic spatial distortion.
(d) The gravitational pull of the Earth.
(e) Nothing! Time travel into the future is theoretically impossible.

51. Suppose that two super accurate atomic clocks, called clock A and clock B, are synchronized on Earth so that they agree exactly. Now imagine that clock B is placed aboard a space vessel and sent to Mars and back. The clock readings are compared after the ship returns. What do we find?

(a) Clocks A and B still agree precisely.
(b) Clock A is behind clock B.
(c) Clock A is ahead of clock B.
(d) Any of the above, depending on the extent to which the ship accelerated during its journey.
(e) None of the above

52. Which of the following terms does not refer to a type of variable star?

(a) RR Lyrae
(b) Mira
(c) White dwarf
(d) Eclipsing binary
(e) Cepheid

53. In the Milky Way galaxy, the Solar System is believed to be located

(a) In one of the spiral arms halfway from the center of the disk to the edge.
(b) High above the plane of the galaxy’s disk.
(c) In a black hole at the center.
(d) Between spiral arms at the outer edge of the galaxy’s disk.
(e) In the central bulge but not within the central black hole itself.

54. In today’s conventional model of the atom,

(a) Electrons orbit in circles and all in the same plane.
(b) Electrons orbit in ellipses with the nucleus at one focus.
(c) Electrons and protons comprise the nucleus.
(d) There are more electrons than protons.
(e) Electrons exist in spherical shells surrounding the nucleus.

55. When astronomers talk about “dark matter,” they are referring to

(a) Clouds of dust in interstellar space.
(b) Planets and moons in the Solar System.
(c) black-dwarf stars.
(d) Asteroids, meteoroids, and comets that are too far from the Sun to glow.
(e) Hypothetical cosmic “stuff” that has mass but cannot be seen.

56. Fill in the blank in the following sentence: “When a space ship moves at a speed approaching the speed of light relative to an observer, that observer will see a clock on the ship appear to __________.”

(a) Run too fast
(b) Stop
(c) Run too slowly
(d) Run infinitely fast
(e) Run at normal speed

57. A distance of 1 Mpc is

(a) 0.001 parsec.
(b) 1,000 parsecs.
(c) 1 million parsecs.
(d) 1 billion parsecs.
(e) Dependent on the angle at which it is measured.

58. If a neutron star collapses to within its event horizon,

(a) Electromagnetic rays leaving the surface at low angles are trapped.
(b) Electromagnetic rays cannot escape from the surface into outer space.
(c) It rebounds and explodes, causing a supernova.
(d) It disappears without a trace.
(e) No! A neutron star cannot collapse to within its event horizon.

59. Suppose that an astronomer finds an object that looks like a glowing ball of stars, and its spectrum is significantly red-shifted. The astronomer concludes that the object is

(a) An elliptical galaxy.
(b) A quasar.
(c) A black hole.
(d) A globular cluster.
(e) An emission nebula.

60. Globular star clusters are believed to be

(a) Galaxies far from the Milky Way.
(b) Comprised of young stars.
(c) comprised of old stars.
(d) Approaching us at high speed.
(e) Receding from us at high speed.

61. A telescope can be made using

(a) A concave objective lens and a convex eyepiece lens.
(b) A convex objective lens and a concave eyepiece lens.
(c) A convex objective mirror and a concave eyepiece lens.
(d) A concave objective lens and a concave eyepiece lens.
(e) Any of the above.

62. Which of the following will not present a problem for interstellar travelers?

(a) Cosmic radiation
(b) Boredom
(c) Meteoroids
(d) Maintaining a supply of food and water
(e) All of the above will be cause for concern.

63. Which of the following statements is false?

(a) A convex lens can bring parallel light rays to a focus.
(b) A concave mirror can collimate light rays from a point source.
(c) A convex mirror can be used as the main objective in a reflecting telescope.
(d) A concave lens makes close-up objects appear smaller.
(e) A convex lens can be used as the main objective in a refracting telescope.

64. What color of light is best for referring to star charts and other data when observing the heavens on a moonless night?

(a) Red
(b) Green
(c) Blue
(d) White
(e) It does matter.

65. A cloud chamber can be used to detect

(a) Cosmic particles.
(b) IR radiation.
(c) UV radiation.
(d) Microwaves.
(e) All of the above.

66. In a good pair of binoculars, the lenses

(a) Reflect most of the light internally.
(b) Have aluminized surfaces.
(c) Are polarized.
(d) Are coated to minimize reflection of light.
(e) Are tinted to filter out glare.

67. One of the most annoying problems of a Galilean refractor, which uses a con¬cave lens as the eyepiece, is the fact that

(a) The image appears upside-down.
(b) The image appears laterally reversed.
(c) The apparent field of view is narrow.
(d) Focusing is critical.
(e) The objective mirror is difficult to adjust.

68. What is a telechir?

(a) A long-distance radio transmitter for interplanetary communication
(b) A system for remotely controlling a space probe
(c) A shuttle craft that can be used for transportation between a large space ship and the surface of a planet, moon, or asteroid
(d) A remotely controlled robot
(e) A virtual-reality computer program

69. A rich-field Newtonian reflector

(a) Has relatively high magnification.
(b) Has a relatively large objective mirror.
(c) Has a relatively small /-ratio.
(d) Requires a Barlow lens.
(e) Requires a focal reducer.

70. Visible-light wavelengths are commonly denoted in

(a) Light-years.
(b) Kilometers.
(c) Meters.
(d) Centimeters.
(e) Nanometers.

71. Suppose that a certain material transmits light at a speed of 150,000 km/s, What is its index of refraction, accurate to three significant figures?

(a) 0.500
(b) 0.805
(c) 1.00
(d) 1.24
(e) 2.00

72. A Keplerian refracting telescope has an objective lens with a focal length of 1,000 mm. A 10-mm eyepiece is used in conjunction with a 2X Barlow lens. The magnification of this telescope is

(a) 20X.
(b) 50X.
(c) 100X.
(d) 200 X.
(e) Impossible to calculate without more information.

73. One of the most serious challenges that will face the designers and operators of matter-antimatter spacecraft propulsion systems is

(a) Keeping the antimatter contained while it is stored.
(b) Preventing the ship from exceeding the speed of light.
(c) The relative inefficiency of matter-antimatter reactions.
(d) Keeping the temperature high enough for reactions to occur.
(e) Building an entire space ship out of antimatter.

74. The interferometer is

(a) A special high-resolution radio telescope.
(b) A device for splitting light into colors.
(c) An instrument for detecting x-rays.
(d) A means of minimizing radio noise.
(e) an antenna for transmitting signals through the ionosphere.

75. On an interplanetary journey, food will come mainly from

(a) Supplies carried or delivered from Earth.
(b) Mineral matter gathered from meteoroids, asteroids, and comets.
(c) Extraterrestrial sources.
(d) Water and vitamin pills.
(e) Intravenous feeding.

76. The wavelength of a light beam is inversely proportional to its

(a) Energy.
(b) Bandwidth.
(c) Intensity.
(d) Frequency.
(e) Period.

77. A disadvantage of using robots in place of human astronauts for long-distance journeys into space is, arguably, the fact that

(a) The electronic circuits in robots are sensitive to cosmic radiation.
(b) Sending robots to celestial destinations is not romantic.
(c) Robots are too heavy and bulky to transport into space.
(d) Robots require electrical power to function, but humans do not.
(e) Robots could bring computer viruses back to Earth.

78. An SCT has an objective mirror with an effective focal length of 2,000 mm. A 40-mm eyepiece is used in conjunction with a focal reducer/corrector that reduces the /-ratio by 37 percent. The magnification of this configuration is

(a) 18.5X.
(b) 31.5X.
(c) 50 X.
(d) 68.5X.
(e) impossible to determine without more information.

79. Which of the following statements is false?

(a) A glass prism bends green light more than it bends orange light.
(b) The focal length of a simple glass convex lens is shorter for green light than for orange light.
(c) Dispersion occurs when white light passes through a simple glass lens.
(d) The index of refraction of glass depends on the color of the light shining through it.
(e) All of the above statements are true.

80. Fill in the blank to make the following sentence true: “The _________ temperature of a celestial object is determined by examining its radiation intensity at various wavelengths.”

(a) Infrared
(b) Convective
(c) Spectral
(d) Apparent
(e) Fahrenheit

81. A fork mount and wedge consists of

(a) An az-el mount that is tilted so that its azimu th axis points at the celestial pole.
(b) An azel mount that is tilted so that its elevation axis points at the celestial pole.
(c) A German equatorial mount that is tilted so that its right-ascension axis points at the zenith.
(d) A German equatorial mount that is tilted so that its declination axis points at the zenith.
(e) None of the above.

82. The maximum diameter of a refracting telescope is limited, in practice, by

(a) Lens sag.
(b) Spherical aberration.
(c) Paraboloidal aberration.
(d) Focal length.
(e) Dispersion.

83. Suppose that you travel into space at a speed arbitrarily close to the speed of light for a vast distance and then return to Earth. Which of the following scenarios is impossible?

(a) Your parents have not yet been bom.
(b) All the classmates you knew in high school are years older than you.
(c) The climate of the Earth has changed.
(d) Humans have become extinct.
(e) The Sun has died.

84. In order to observe the Cosmos at x-ray wavelengths, it is necessary to

(a) Get above Earth’s atmosphere.
(b) Use special color filters.
(c) Use a telescope with a large /-ratio.
(d) Find a location far away from city lights.
(e) find a location where there is little rf interference.

85. To keep the rotation of Earth from causing celestial objects to drift out of a telescope’s field of view, you can use

(a) A Dobsonian mounts.
(b) A right-ascension mount.
(c) A German equatorial mount.
(d) An equatorial mounting table.
(e) a clock drive.

86. Imagine a solid sphere of glass, perfectly transparent and perfectly uniform, with a spherical hollow space in the exact center. Imagine a lightbulb, call it Lamp A, with a point-source filament located at the center of the spherical hollow space and therefore also at the center of the whole sphere of glass. Imagine a second lightbulb in the open air, also with a point-source filament; call it Lamp B. How do the rays of light from the two lamps compare in their behavior?

(a) The rays from both lamps radiate outward in straight lines and in exactly the same way.
(b) The rays from Lamp A are reflected totally inside the cavity within the sphere of glass, but the rays from Lamp B radiate outward in straight lines.
(c) The rays from Lamp A converge to a point somewhere outside the sphere of glass, but the rays from Lamp B radiate outward in straight lines.
(d) The rays from Lamp A diverge more when they emerge from the sphere of glass compared with the rays from Lamp B that do not have to pass through the glass.
(e) It is impossible to say without more information.

87. A device that bends light, making refractors and SCTs easier to look through when observing objects high in the sky, is called

(a) A Kellner eyepiece.
(b) A finder.
(c) A Barlow lens.
(d) A focal reducer.
(e) A star diagonal.

88. Which of the following instruments can be used to analyze celestial objects in the UV part of the spectrum?

(a) A radar telescope
(b) A spectrophotometer
(c) An interferometer
(d) A Keplerian refractor
(e) A Galilean refractor

89. Most telescope eyepieces have focal lengths ranging from approximately

(a) 0.4 to 4 mm.
(b) 4 to 40 mm.
(c) 40 to 400 mm.
(d) 40 cm to 4 m.
(e) 4 to 40 m.

90. A Cassegrain reflector

(a) Has a concave objective mirror and a flat secondary mirror.
(b) Has a concave objective mirror and a convex secondary mirror.
(c) Has a longer tube than an equivalent Newtonian reflector.
(d) Suffers from lens sag if the diameter of the objective is too large.
(e) Has the eyepiece mounted in the side of the tube.

91. Fill in the blank to make the following sentence correct: “For best viewing, the ___________ of a pair of binoculars should be the same as the diameter of the pupils of the observer’s eyes when adjusted to the darkness.”

(a) objective-lens diameter
(b) Eyepiece diameter
(c) Magnification
(d) Exit pupil
(e) Focal length

92. One theory concerning the nature of x-ray stars suggests that they consist of

(a) diffuse gas and dust congealing into new stars.
(b) Remnants of supernovae.
(c) Binary systems in which a neutron star pulls matter from a normal star.
(d) Cool stars with intense magnetic fields.
(e) Pairs of neutron stars in mutual orbit.

93. In an interplanetary or intergalactic spacecraft, the oxygen supply can be supplemented by

(a) Burning flammable materials.
(b) Electrolysis of water.
(c) Combining water with hydrogen.
(d) Hydrogen fusion.
(e) None of the above.

94. A Cassegrain reflector has an objective measuring 25 cm in diameter. The magnification of the telescope is 250X. What is the /-ratio of this instrument?

(a) //25
(b) //250
(c) //10
(d) //0.10
(e) It cannot be calculated from this information.

95. Which, if any, of the following (a, b, c, or d) has not been suggested as a good reason for humanity to venture into space?

(a) Extraterrestrial objects contain natural resources we can use.
(b)We should strive to encounter and learn from extraterrestrial beings.
(c) Relativistic space travel will allow us to travel back in time and correct our past mistakes.
(d) The Sun will eventually die and we will need to find a new home.
(e) All of the above have been suggested as good reasons for humanity to ven¬ture into space.

96. Radar astronomy has proven valuable in mapping the surface of

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

97. The Bussard ramjet is a proposed form of

(a) Aircraft propulsion system.
(b) hydrogen-fusion propulsion system.
(c) Chemical propulsion system.
(d) matter-antimatter propulsion system.
(e) laser-beam propulsion system.

98. When light from the Sun shines on a spherical, reflective object such as a steel ball bearing, the reflected rays

(a) Are all parallel.
(b) Diverge.
(c) Converge.
(d) Focus to a point hot enough to start fires.
(e) Behave unpredictably.

99. When an astronaut lives for a long time at zero-g,

(a) The body becomes stronger because it doesn’t have to constantly work against the pull of gravity.
(b) The bones lose calcium, which is excreted in the urine; this weakens the skeleton and can cause kidney stones.
(c) The lung capacity increases because the thin air requires that they grow larger to get enough oxygen.
(d) The body gradually loses its need for sleep so that by the end of a long journey, space travelers can stay awake and alert indefinitely.
(e) Nothing in particular happens to the body.

100. Karl Jansky was the first experimenter to discover radio noise coming from outer space. He found especially high levels of RF energy when his antennas were aimed at

(a) The Moon.
(b) The north celestial pole.
(c) The center of the galaxy.
(d) The horizon.
(e) The zenith.