Final Exam Fall 2002
Multiple Choice Questions (2 pts. each)
Choose the best answer to each of the following questions using what you have learned in ASTR 101. Indicate your choice on the scantron.
1. The largest galaxies are
A. giant spirals found near the Great Attractor.
B. giant spirals in clusters with quasars.
C. giant ellipticals in the Local Group.
D. giant ellipticals in the centers of the voids.
E. giant ellipticals near the center of galaxy clusters.
2. Jupiter’s Great Red Spot is
A. a hole where Comet Shoemaker Levy 9 struck the planet.
B. the gas plume of a super volcano.
C. a long-lived storm in the jovian atmosphere.
D. an enormous lake of unknown liquid red compounds.
E. an optical illusion.
3. The Sun set an hour ago. You look west and see the Moon. The phase must be
A. full.
B. waxing gibbous.
C. waning gibbous.
D. waxing crescent.
E. waning crescent.
4. We cannot photograph the central region of the Milky Way using optical telescopes (visible light). Why?
A. The center of the Milky Way is billions of light years away, so no visible
photons have had time to get here.
B. There is dust blocking our view of the Milky Way’s center.
C. There is dark matter blocking our view of the Milky Way’s center.
D. The stars have all been sucked into the supermassive black hole that lies there.
E. The Sun lies in that direction so the sky in this region is always too bright to
see.
5. Henrietta Leavitt’s discovery of a relationship between period and luminosity of Cepheid variable stars gave astronomers a new way to
A. determine the masses of stars.
B. find the ages of stars.
C. find the age of the universe.
D. measure the distances to these stars.
E. determine the composition of these stars.
6. The 65 million year old clay layer containing Iridium that is observed all over the Earth is cited as support for
A. the formation of the Moon.
B. continental drift.
C. magnetic reversal.
D. a large asteroid impact.
E. the presence of an atmosphere rich in oxygen.
7. An eclipse occurred in Australia. The phase of the moon observed in College Park that evening is full. What kind of eclipse occurred in Australia?
A. a lunar eclipse
B. an annular eclipse
C. a solar eclipse
D. an umbral eclipse
E. a prenumbral eclipse
8. If the mass of a supermassive black hole is 40 million solar masses, what is the radius of its event horizon?
A. 40 million km.
B. 120 million km.
C. 400 million km.
D. 1,200 million km.
E. 1,600 million km.
9. Shapley knew that the Sun couldn’t be located at the center of the Milky Way galaxy because he noticed that
A. globular star clusters were not evenly distributed around the sky.
B. globular star clusters defined a flat disk-shaped region.
C. there wasn’t a black hole nearby.
D. pulsars had a uniform distribution around the sky.
E. pulsars had a non-uniform distribution around the sky.
10. The argument was made by Frank Drake that the stars most likely to have planets with extraterrestrial technical civilizations are
A. F to M giants.
B. B to A main sequence.
C. G to K main sequence.
D. M main sequence.
E. white dwarfs.
11. Which of the following best describes the Sun’s location in our galaxy?
A. in a spiral arm about 28,000 light years from galactic center.
B. in a globular star cluster above galactic center.
C. near galactic center.
D. in an open star cluster at the galaxy’s outer limit.
E. in the galactic halo.
12. When the Moon is a thin crescent, ______is easily visible.
A. an aurora
B. the ozone hole
C. earthshine
D. its atmosphere
E. its far side
13. From College Park, which of the following planets could NEVERbe seen at midnight?
A. Mars
B. Jupiter
C. Saturn
D. Mercury
E. all of the above can be seen at midnight
14. You have 5 identical lamps, but can vary the temperature of each filament by changing the resistance. The hottest lamp would be the one emitting the greatest number of ______photons.
A. red
B. orange
C. yellow
D. green
E. blue
15. From Santa’s Workshop located at the North Pole, an observer would see which star very near the zenith?
A. Algol
B. Alpha Centauri
C. Vega
D. Polaris
E. Sirius
16. In fusion reactions, energy is liberated as
A. hydrogen heats up.
B. some mass is converted to energy.
C. radioactive helium is produced.
D. fissionable products decay.
E. chemical bonds are broken.
17. The surface of Venus has been mapped extensively using
A. optical telescopes on Earth’s surface.
B. optical telescopes in space.
C. radar imaging from spacecraft.
D. landing spacecraft.
E. infrared sensors on Earth.
18. Which of the following changes occurs immediately after the development of a hydrogen burning shell inside a star like the Sun?
A. The star collapses to a neutron star and then it blows up.
B. The star ejects a planetary nebula and planets form.
C. The star emits strongly in the infrared and becomes a protostar.
D. The star’s outer layers expand and it becomes a red giant.
E. A black hole forms.
19. The cause of a meteor shower like the Leonids in November is due to
A. sunspot activity and geomagnetic disturbances.
B. unstable weather conditions brought about by El Nino.
C. Earth passing through a spiral arm in our galaxy.
D. Earth crossing a comet’s orbit and particles that came off the comet vaporize.
E. Earth moved through a nebula containing dust particles that vaporize.
20. Today the Moon is midway between first quarter and full phases. When will the Moon rise?
A. noon
B. 3 PM
C. 6 PM
D. 9 PM
E. midnight
21. Aristotle accepted the geocentric theory largely because
A. he couldn’t detect any stellar parallax.
B. he had not heard of Ptolemy’s epicycle theory.
C. he was aware of precession and needed an explanation.
D. only this theory accounted for both the Earth’s rotation and the seasons.
E. he couldn’t observe the center of the galaxy.
22. Compared to the Earth, Venus has an overabundance of carbon dioxide in its atmosphere, because
A. Venus has more volcanoes which expelled this gas into its atmosphere.
B. Venus has a greenhouse effect while Earth does not.
C. Venus never had large quantities of liquid water present on its surface.
D. differentiation couldn’t happen on Venus so this gas remained in the
atmosphere.
E. more comets hit Venus and vaporized than hit Earth.
23. Astronomers are convinced that liquid water existed on Mars in the past, because
A. huge subsurface deposits of ice have been seen with X-ray telescopes.
B. during each martian summer large lakes form as the polar cap melts.
C. there is a huge amount of water vapor in martian clouds.
D. the surface has water-cut channels on it.
E. we observe dark vegetation growing along the canals.
24. Depletion of the Earth’s ozone layer in the stratosphere would have the effect of
A. increasing the amounts of carbon dioxide in Earth atmosphere.
B. triggering another ice age.
C. increasing volcanic activity in the polar regions.
D. increasing the amount of auroral activity.
E. allowing more ultraviolet radiation to reach Earth’s surface.
25. The mass limit for a white dwarf star is 1.4 solar masses. Why?
A. Above this mass the neutron pressure cannot balance gravity.
B. Above this mass the electron pressure cannot balance gravity.
C. Below this mass the star becomes a pulsar.
D. Below this mass the star becomes a black hole.
E. The star would become a supernova below this mass.
26. Which of the following lists is correctly arranged in order of increasing density?
A. Jupiter, the Moon, Earth, a white dwarf, a neutron star
B. the Moon, Earth, a white dwarf, Jupiter, a neutron star
C. a neutron star, the Moon, Jupiter, Earth, a white dwarf
D. the Moon, Earth, Jupiter, a neutron star, a white dwarf
E. Jupiter, a neutron star, a white dwarf, the Moon, Earth
27. Which of the following observations provided early support for Einstein’s theory of general relativity?
A. discovery of black holes
B. position of a star at the edge of the Sun during a solar eclipse
C. discovery that nothing travels faster than light
D. the solution to the equation E = mc2
E. the discovery of pulsars
28. The two planets that are about two degrees apart and visible in the early morning sky are
A. Venus and Jupiter
B. Jupiter and Saturn
C. Uranus and Neptune
D. Mars and Venus
E. Mercury and Mars
29. Which of the following is always true of a K5 red giant and a K5 main sequence star? They have the same
A. luminosity.
B. kind of fusion taking place in the core.
C. surface temperature.
D. age.
E. mass
30. Auroras are much more commonly observed in regions located close to the poles on Earth because
A. charged solar particles are directed by Earth’s magnetic field to these regions.
B. sunlight is reflected off the polar caps near the poles.
C. one of the poles is always pointing toward the Sun.
D. during a quarter moon both Sun and Moon are at right angles.
E. the Earth’s gravity is stronger near the poles.
31. Today the Sun will dip below the horizon at 4:37 PM. Actually it will be visible an additional 4 minutes. Why?
A. because we live in a northern latitude
B. due to atmospheric refraction
C. due to atmospheric reflection
D. because the Sun is south of the celestial equator
E. because the Sun is north of the celestial equator
32. Navigators can find their latitude on Earth by observing the angle between the
A. celestial equator and either pole.
B. celestial pole and horizon.
C. two celestial poles.
D. Sun and the Moon.
E. Sun and the ecliptic.
33. The Sun will spend most of its life as a
A. Big Mac.
B. red giant.
C. main sequence star.
D. protostar.
E. black hole.
34. Absorption lines in stellar spectra provide information on a star’s
A. radial motion.
B. composition.
C. temperature.
D. all of the above.
E. only answers A and B
35. The peak or maximum wavelength that you are emitting right now lies in which portion of the electromagnetic spectrum?
A. radio
B. infrared
C. visible
D. ultraviolet
E. X-ray
36. In 1054 AD Chinese astronomers as well as Native Americans and Arabs observed a new star appear in the constellation of Taurus. It faded gradually in brightness. Today when we view this location with a telescope we see
A. a black hole.
B. a nova.
C. a supernova remnant.
D. a planetary nebula.
E. a white dwarf.
37. A “shooting star” or “falling star” is really
A. a star moving a great speed.
B. a comet approaching the Sun.
C. a comet moving away from the Sun.
D. a meteor.
E. an asteroid.
38. A comet’s gas tail results when
A. part of the comet drifts in the direction opposite to the comet’s motion.
B. the solar wind pushes some of the coma in the direction away from the Sun.
C. gravitational forces pull loosely held material from the Sun toward the comet.
D. tidal forces tear apart the comet.
E. the comet nears aphelion.
39. The Moon’s orbit is slightly inclined to Earth’s orbit. This explains
A. why the Sun moves along the ecliptic.
B. why we never see the lunar far side.
C. why we see the Moon sometimes during the day.
D. why earthshine occurs.
E. why a solar eclipse doesn’t occur every month.
40. There have been 102 extrasolar planets discovered since 1995. How were they detected?
A. analysis of radio signals sent by an alien civilization
B. photographed with the Hubble Space Telescope
C. photographed with large telescopes on Earth’s surface
D. observed as tiny dots moving across a star’s surface
E. spectroscopically through their tiny gravitational effects
41. It is easier to launch a rocket off the Moon than off the Earth because
A. there is no gravity on the Moon.
B. there is no atmosphere on the Moon.
C. there is less inertia on the Moon.
D. there is less gravity on the Moon.
E. there is more air resistance on the Moon.
42. Magnetic fields inhibit the convective flow of energy to the Sun’s photosphere and disrupt the granulation pattern. This process leads to the formation of
A. prominences.
B. sunspots.
C. meteorites.
D. hydrogen absorption lines.
E. hydrogen emission lines.
43. The “M” in M31 (the Andromeda Galaxy) refers to
A. Hubble’s classification for this galaxy.
B. the galaxy’s spectral type.
C. modulus—meaning the distance modulus is 31.
D. the Messier Catalog.
E. metallic content.
44. The core of an aging massive supergiant is
A. layered with lighter elements in the center.
B. layered with heavier elements in the center.
C. uniformly composed of hydrogen and helium.
D. uniformly composed of helium.
E. composed of molecules containing mostly carbon and iron.
45. When two galaxies collide with one another their shapes are distorted by
A. collisions of individual stars.
B. a gigantic explosion resulting from such a collision.
C. gravitational forces that they exert on each other.
D. the strong nuclear force.
E. the expansion of the universe pulling them apart.
46. ______hypothesis that the planets move in elliptical orbits was deduced after his careful study of ______data concerning the motion of Mars collected over many years.
A. Kepler’s; Tycho’s
B. Copernicus’s; Aristarchus’s
C. Newton’s; Einstein’s
D. Ptolemy’s; Aristotle’s
E. Galileo’s; Hubble’s
47. Newton’s three laws of motion or gravitational theory fail to explain or describe
A. escape velocity.
B. the rocket trike experiment.
C. the feather and ball dropped in a vacuum.
D. inertia.
E. the generation of Earth’s magnetic field.
48. The rotation curve for a spiral galaxy is given below. What have astronomers deduced by studying such curves?
Diagram will be provided in Discussion Section
A. Quasars have tremendous luminosities.
B. The disks of many galaxies are tilted away from us.
C. Atmospheric refraction caused these profiles.
D. There must be dark matter in the halos of these galaxies.
E. The interstellar medium doesn’t rotate around the center of these galaxies.
49. A spiral galaxy is identified. Its angular diameter is only 1/10 that of the Andromeda Galaxy. If the distance to the Andromeda Galaxy is 2 million light years and assuming that the identified spiral is approximately the same physical size as the Andromeda Galaxy, estimate the spiral galaxy’s distance.
A. 0.2 million light years
B. 2 million light years
C. 10 million light years
D. 20 million light years
E. 200 million light years
50. Given the positions of Stars A and B as shown below relative to the Earth’s position, the spectrum that you would observe on Earth is labeled with the letter ______.
Diagram will be provided in discussion section
Short Answer Questions (50 pts.)
Please answer each of the following questions as completely as you can using what you have learned in ASTR 101.
51. Hubble was one of the first astronomers to extensively use the Mt. Wilson 100-inch telescope. Discuss his discoveries in each of the following areas:
a) How did he determine the distance to the Andromeda spiral nebula? (3 pts.)
b) How did he set up his classification system for galaxies? (and give the main classes) (4 pts.)
c) How did he discover/develop the relation known as Hubble’s Law? (4 pts.)
52.. a) Describe how X-rays can be produced by a black hole’s accretion disk. (4 pts.)
b) Our best maps of the Milky Way Galaxy’s structure are made using 21 centimeter radiation. How is 21 centimeter radiation produced? (4 pts.)
c) Based on the results of 21 centimeter mapping, how is our galaxy classified using Hubble’s system? (2 pts.)
53. a) What conditions (give 3) on Earth are considered to be crucial for “life as we know it”? (3 pts.)
b) Where in our Solar System besides Earth is the most likely place to search for life (current or past life)? Choose 1 place and support your choice. (3 pts.)
c) Do you think that N (number of civilizations capable of communicating over interstellar distances) from the Drake Equation is a large or small number? Use what you have learned about the Drake Equation to support your choice. (4 pts.)
EXTRA CREDIT (2 pts. maximum)
Explain how the “raisin bread analogy” demonstrates that the Milky Way galaxy is not located at the center of the universe.
54. a) With the aid of a labeled sketch, explain how the observations of pulsars are produced. (4 pts.)
b) Even though our Sun is very massive with a tremendous amount of gravity it does not collapse to become a black hole. Why not? Explain. (4 pts.)
c) Explain why we experience different seasons in College Park. (3 pts.)
55. a) What do astronomers mean when they say that the “universe is expanding?”
(4 pts.)
b) Why does the observation of the cosmic background radiation support the Big Bang Theory? (4 pts.)
EXTRA CREDIT (2 pts. maximum)
What are the two possible futures for the Universe?
EXTRA CREDIT (2 pts. maximum)
The Winter Solstice occurs precisely at 8:14 PM EST on Dec. 21. Where is the Sun at this precise time? (Below our horizon is NOT the answer I’m looking for!)