This quiz covers the chapters on the solar system’s planets (etc.) and an introduction to our own and other galaxies. 1…

1 . The Moon’s average density is about 3 g/cm^3, while the Earth has about 5 g/cm^3. Which of the following conclusions can be drawn from this comparison?
A. The Moon must have more hydrogen
B. The Moon does not have water
C. The Earth has more iron and nickel
D. The Moon has a larger core
E. The Earth and the Moon were formed at different times

2. Which of the following facts could result from the Moon’s slow rotation and the lack of a substantial iron core?
A. The Moon does not have a substantial atmosphere
B. The Moon does not have active volcanoes
C. The Moon has essentially no magnetic field
D. The absence of seasons in the Moon
E. All of the choices are correct

3. Which of the following facts supports the hypothesis that the surface features of the Moon did not change substantially over the past 3 billion years?
A. The Moon rotates slowly.
B. The Moon does not have a magnetic field.
C. The Moon does not have an atmosphere.
D. The Moon rocks are not dense.
E. All of the choices are correct

4. What is the origin of regolith?
A. Material deposited by volcanic eruptions
B. Material eroded by dust storms
C. Material fragmented by seismic waves
D. Rock crushed by impacts
E. The origin is unknown

5. What is the composition of regolith?
A. Anorthosite fragments in the highlands and basaltic in the maria
B. Anorthosite fragments in the maria and basaltic in the highland regions
C. Limestone fragments in maria and iron in the highlands
D. The composition is mainly volcanic rock, and is the same in both maria and highlands.
E. Regolith is iron rich and the same in both maria and highlands.

6. Why do astronomers believe that the lunar maria are younger than the highlands?
A. The maria are more cratered.
B. The maria are lighter in color.
C. The maria have fewer craters.
D. The highlands have evidence of ancient river beds

7. What is the probable origin of some mountain chains observed near the lunar maria?
A. They were formed by plate tectonics.
B. They are ancient volcanoes.
C. They were formed by material that pushed up by the impact that created the maria.
D. They are lava outcrops that pushed up through the crust

8. The absence of plate tectonic motion on the Moon can be explained by the fact that:
A. The Moon has less iron in the core than the Earth.
B. The Moon does not have active volcanoes.
C. The Moon interior is cooler than the Earth’s and therefore there is no heat to create convective motion.
D. The material forming the crust of Moon is very different and much stronger than Earth’s crust

9. Assuming that the Earth and the Moon formed at the same time, what conclusions can be drawn regarding the present temperature of their cores?
A. Since they formed at the same time, the interior temperatures must be the same.
B. The Earth’s interior is cooler, because the Earth has atmosphere and surface water.
C. The Moon’s interior temperature is higher, because the Moon comes closer to the Sun.
D. The Moon, being smaller, has cooler interior, because smaller objects cool off faster than larger objects.
E. The Moon’s interior is hotter, due to intense meteoric bombardment

10. Astronomers attribute the lack of atmosphere on the Moon to:
A. The lack of surface water.
B. The lack of meteoric/comet impacts on the Moon.
C. The absence of volcanic activity.
D. The low gravitational force of the Moon, which is too weak to keep gases from escaping
E. Both C and D

11. What conclusive proof do we have that the Moon has essentially zero magnetic field?
A. Auroras are not observed on the Moon.
B. The Moon’s iron core is small.
C. The Moon rotates slowly.
D. Magnetic field measurements taken by the Apollo astronauts.
E. None of the choices are correct; the Moon has a substantial magnetic field due to the tidal interaction with the Earth

12. Which of the following changes would you expect to observe if the Moon was orbiting on the ecliptic?
A. A lunar eclipse every full Moon
B. A solar eclipse every new Moon
C. Both sides of the Moon would be visible.
D. All of the choices are correct.
E. Only a lunar eclipse every full Moon and a solar eclipse every new Moon are correct

13. During a solar eclipse on Earth an astronomer stationed on the near side of the Moon would observe:
(Hint: Is a solar eclipse visible from all parts of the Earth?)
A. Total “Earth eclipse”
B.A small shadow covering about 150 miles in size of the Earth’s disk
C. A partial solar eclipse
D. No effects would be detectable from the Moon.

14. A successful theory of the solar system must be able to primarily explain:
A. The origin of life.
B. The fact that the planetary orbits lie approximately in the same plane.
C. The fact that Mars has satellites.
D. The fact that Pluto’s orbit is very elliptical

15. The study of extra-solar planetary systems provides a good comparison to test the nebular hypothesis. Which of the following statements is not a critical issue resulting from such comparison?
A.The extra-solar systems do not obey Bode’s law, therefore the nebular hypothesis is incorrect.
B. Very massive planets are found very near the stars of extra-solar systems.
C. The orbits of extra-solar planets can be very elliptical, suggesting that planets may migrate.
D. All the above suggest inward migration
E. Only B and C are significant

16. Which of the following is true of the terrestrial planets?
A. They are composed of rock.
B. They have solid surfaces.
C. They are small compared to jovian planets.
D. They have fewer satellites than the jovian planets.
E. All of the choices are correct

17. Which of the following is true of the jovian planets?
A. They have thick atmospheres.
B. They are much larger than the terrestrial planets.
C. They have more hydrogen and helium than the terrestrial planets.
D. They have more satellites than the terrestrial planets.
E. All of the choices are correct.

18. Which of the following explains the fact that the jovian planets have overwhelmingly more hydrogen and helium than the terrestrial planets?
A. Hydrogen and helium were not present in the central part of the solar nebula.
B. The spin of the solar nebula dispersed the gases to the outer part of the disk.
C. The higher temperatures near the center of the solar nebula prevented the condensation of hydrogen and helium in the inner part of the disk.
D. The escape velocity was higher near the Sun

19. Which of the following explains the rocky nature of the inner planets?
A. The lighter elements (hydrogen and helium) were sucked-in by the Sun’s gravity.
B. The Sun’s gravity attracted the rocks to the inner part of the solar system.
C. Only the rocky material could condense at the higher temperatures of the inner part of the solar nebula.
D. As the solar nebula was spinning, the light gasses were tossed to the outer parts of the disk

20. According to the nebular hypothesis, which of the following sequences of events are chronologically correct?
A. Solar nebula, interstellar cloud, collisions between planetesimals, accretion, planets
B. Interstellar cloud, solar nebula, accretion, collisions between planetesimals, planets
C. Interstellar cloud, accretion, solar nebula, collisions between planetesimals, planets
D. Accretion, solar nebula, interstellar cloud, collisions between planets, planetesimals
21. What conclusion can be drawn from the fact that some planets with solid surface and satellites have impact craters?
A. Planets and their satellites were showered by planetesimals.
B. The young planets had softer surfaces.
C. Volcanoes were very active in the early stages of planet formation.
D. The Sun went through several explosions, ejecting material that scarred the planets and satellites.
22. Why was the recent discovery that planets more massive than Jupiter orbit near-by stars in small orbits surprising?
A. Because according to the nebular hypothesis, massive planets should only form away from their star
B. The density of these planets is very high.
C. According to the nebular hypothesis, planets cannot be larger than Jupiter.
D. The orbits of these planets are very inclined

23. Which of the following is the strongest evidence in support of the hypothesis that the solar system was formed by the collapse of a gas and dust nebula?
A. Bode’s law
B. Images of stars with gas and dust disks surrounding them
C. The existence of large clouds
D. The discovery of extra-solar planets

24. Comets are _____ while asteroids are _____.
A. icy; rocky
B. large; small
C. rocky; icy

25. Astronomers estimate that the age of the solar system is about ____ years.
A. 4.6 million
B. 4.6 billion
C. 1.6 billion
D. 4.6 trillion
E. 10 million

26. Which of the following statements best describes Mercury’s atmosphere?
A. Mercury has essentially no atmosphere.
B. Mercury’s atmosphere is similar to the Earth’s atmosphere.
C. Mercury has a thin methane atmosphere.
D. Mercury consists of hydrogen and helium.

27. In what way does the surface of Mercury differ from the Moon’s surface?
A. Mercury’s surface is not cratered.
B. Much of Mercury’s surface is covered with congealed lava
C. Mercury’s surface has more volcanoes.
D. Mercury’s surface was formed more recently.

28. The surface temperature on Mercury’s equator shows extreme variation between day and night. This extreme variation results from:
A. its slow rotation
B. The lack of atmosphere.
C. The proximity to the Sun.
D. All of the choices are correct.
E. The proximity to the Sun and the lack of atmosphere are the correct choices

29. Compared to the other terrestrial planets, Mercury is rich in iron compounds. Which of the following are probable explanations for the iron abundance in Mercury?
A. Mercury’s magnetic field attracted the iron.
B. Iron compounds condensed more readily than silicates in the inner parts of the solar nebula.
C. Part of the silicate mantle of Mercury was blasted off by a planetesimal that impacted Mercury
D. All of the choices are correct.
E. Iron compounds condensed more readily than silicates in the inner parts of the solar nebula and part of the silicate mantle of Mercury was blasted off by a planetesimal that impacted Mercury are possible explanations.

30. Venus appears very bright because:
A. Venus is hot and emits large amount of radiation.
B. The atmosphere of Venus is very transparent.
C. Venus is a very large planet.
D. Venus is covered by a thick layer of clouds.

31. Why is the surface temperature of Venus hotter than Mercury’s?
A. The carbon dioxide in Venus’ atmosphere prevents the heat from escaping.
B. Venus is larger than Mercury.
C. Venus is closer to the Sun.
D. Venus rotates slower than Mercury.
E. Venus has active volcanoes that produce heat

32. Which of the following statements best describes the surface of Venus?
A. The surface is heavily cratered.
B. The surface is covered by extensive maria.
C. The surface is covered by lava flows.
D. The surface shows motion of tectonic plates.

33. What evidence supports the hypothesis that Venus may have active volcanoes?
A. Photographs of volcanic eruptions taken by the Magellan spacecraft
B. Some of the lava flows appear very fresh
C. Electrical discharge activity around the volcanic peaks
D. There are period increases in the sulfur content of its atmosphere
E. All of the choices are correct

34. Which of the following is true of Venus?
A. Venus’ orbital period is long compared to Earth’s
B. Venus orbits the Sun in the opposite direction than the rest of the terrestrial planets.
C. Venus spins slowly compared to the Earth.
D. All of the choices are correct.
E. Both Venus’ orbital period is slow compared to Earth and Venus orbits the Sun in the opposite direction than the rest of the terrestrial planets are true

35. If I were to put quotation marks on each side of “Law” in Bode’s law, which might be an explanation
A. Bode was a charaltan, who only took up astronomy for the money
B. There is no basis for this “law” it could be coincidence
C. It is still just a theory, not a “law”
D. None of the above is true

36. Compared to Earth, the seasons on Mars are more extreme. Which of the following explains the large seasonal variation on Mars?
A. Mars is further away from the Sun.
B. Mars has larger axial tilt than the Earth.
C. Mars has a thinner atmosphere that the Earth.
D. Mars’ atmosphere contains carbon dioxide, which prevents heat from escaping.
E. Mars has large polar caps

37. What evidence supports the hypothesis that cycles of ice-ages have occurred on Mars?
A. The polar caps shrink in the summer.
B. The seasonal variations on Mars are extreme.
C. The Mariner spacecraft recorded extreme temperature variations.
D. The layered structure of the north polar cap of Mars.
E. Mars has an axial tilt similar to the Earth’s

38. Which of the following is a probable explanation for the formation of the Valles Marineris?
A. It is a canyon carved by ancient water flow on the surface of Mars.
B. It is a scarp that formed when the Martian crust cooled and shrunk.
C. It resulted from plate tectonic movement on Mars.
D. It resulted from the stretching of the mantle by the rising of the Tharsis bulge.
E. Both it resulted from plate tectonic movement on Mars and it resulted from the stretching of the mantle by the rising of the Tharsis bulge are probable explanations.

39. Which of the following gases can be found in Jupiter’s atmosphere?
A. Hydrogen
B. Helium
C. Methane
D. Ammonia
E. All of the choices are correct

40. How do we know the internal structure of Jupiter?
A. From the study of seismic waves in Jupiter
B. From the chemical composition of the planet
C. From the average density and the gravitational pull on spacecraft
D. By measuring the volume and the density

41. Which of the following causes the high magnetic field of Jupiter? e
A. Strong Aurora
B. Rapid rotation of the planet
C. Metalic hydrogen in the core of Jupiter, which is highly magnetic
D. It results from the combined effect of the planets rapid rotation and convection in the layer of metallic hydrogen in the planet’s interior

42. Which of the following statements best describes the accepted composition of Jupiter?
A. Jupiter’s core contains more silicates and iron than the entire Earth.
B. Jupiter is devoid of silicates and rocky materiA..
C, Jupiter’s composition is very close to the Sun’s composition.
D. None of the choices are correct.
E. Both Jupiter’s core contains more silicates and iron than the entire Earth and Jupiter’s composition is very close to the Sun’s composition are correct

43. Which of the following statements regarding the rings of Jupiter and Saturn is correct?
A. The rings of Jupiter are made of small particles of rock and dust.
B. The rings of Saturn do not have the same composition everywhere.
C, Saturn has a large number of rings.
D. Both ring systems are very thin.
E. All of the choices are correct

44. What causes the Cassini division in Saturn’s ring system?
A. Electrical charges that push the rings apart, creating a gap
B. The tidal force from Saturn
C. The repeated pull from Mimas, who orbits Saturn with period twice that of particles would orbit in the Cassini division
D. It is a region were dust particles did not accrete

45. Astronomers believe that when moons or comets wander within the Roche limit of a planet, they breakup by the tidal force of the planets. Is it safe for a spacecraft to cross the Roche limit of Mars?
A. No, because it will break apart.
B. Yes, because the Roche limit is a force that exists only in the outer planets.
C. Yes, because Mars does not have a Roche limit.
D. Yes, because the tidal force is too weak to overcome the chemical bonds

46. What evidence supports the hypothesis that the larger satellites of Saturn did not experience significant heating by Saturn?
A. Because the satellites of Saturn formed much later, when the planet cooled off
B. Because their density increases with increasing distance from the planet
C. Because they have about the same density
D. Because Saturn is very cold

47. What causes the blue appearance of the planet Uranus?
A. Uranus’ atmosphere contains methane that strongly absorbs red colors from the sunlight.
B. The planet is covered by an ocean of water.
C, The planet is very hot.
D. The composition of Uranus’ atmosphere is the same as the Earth’s atmosphere that makes the sky blue

48 . Uranus completes an orbit around the Sun every 84 years and spins once every 17 hours, approximately. Which of the following could be observed from the planet Uranus?
A. Season cycle of 84 years near the poles
B. One sunrise every 17 hours on the equator
C, Days lasting several years near the pole tipped towards the Sun
D. Nights lasting several years near the pole tipped away from the Sun
E. All of the choices are correct

49. Compared to Uranus, Neptune has a smaller diameter and more mass. What can we conclude from this comparison?
A. Neptune has higher average density than Uranus.
B. Uranus has higher average density than Neptune.
C, Uranus spins faster and therefore has larger diameter.
D. The statement of the question is incorrect. Uranus is larger and has more mass than Neptune

50. The clouds of Uranus lack the bands that are characteristic of the other Jovian planets. What is the most probable cause for Uranus’ featureless appearance?
A. Uranus is less massive than the other planets.
B. Uranus is colder than the other planets.
C, Uranus rotates slower than the other planets.
D. The surface of Uranus is heated very unevenly due to the extreme axial tilt

51. The discovery of Charon was significant because it allowed astronomers to determine:

A. The distance of Pluto.
B. The age of Pluto.
C, The mass of Pluto.
D. The radius of Pluto
E. Both the mass of Pluto and the radius of Pluto are dcorrect.

52. What is the approximate mass of the Milky Way?
A. About 30 kiloparsecs
B. 10 million solar masses
C. About 100 billion solar masses
D. One trillion kilograms of mass

53. What is a dark interstellar cloud?
A. A cloud heavy with liquid droplets
B. A cloud made of “dark matter”
C. A thick dense cloud of gas and dust
D. A region in the sky seemingly empty of stars
E. Only a region in the sky seemingly empty of stars and a thick dense cloud of gas and dust are correct.

54. Which of the following statements correctly describes the star abundances in the Milky Way galaxy?
A. The majority of the stars observed are main sequence stars.
B. The majority of the stars are young stars.
C. The majority of the stars are cool, low mass stars.
D. All of the choices are correct.
E. Only the majority of the stars observed are main sequence stars and the majority of the stars are cool, low mass stars.

55. Which object extends farther from the nucleus of the Milky Way galaxy?
A. The disk
B. The spiral arms
C. The halo
D. The bulge
E. A population I object

56. Which of the following statements is true about the rotation of the Milky Way Galaxy?
A. It rotates like a solid object (i.e., the farther the object from the center, the higher the speed.
B. It rotates according to Kepler’s laws (i.e., the farther the object from the center, the lower the speed).
C. The speed tends to level off as the distance from the center gets larger.
D. The speed is inversely proportional to the square of the distance.

57. Where is it more likely to find a population II star?
A. In the center of the Milky Way
B. In the spiral arms of the Milky Way
C. In the Halo of the Milky Way
D. At the center of HII regions
E. Both Iin the spiral arms of the Milky Way and in the Halo of the Milky Way are likely.

58. What force holds the stars in orbit in spiral galaxies?
A. The density wave
B. Gravity
C. Dark matter
D. Black holes at the center of the galaxy
E. All of the choices are correct.

59. What is an S0 type galaxy?
A. A large spiral
B. A large elliptical
C. An irregular
D. A disk-shaped galaxy with no evidence of spiral arms
E. None of the choices are correct.

60. Which of the following could explain the origin of the S0 type galaxies?
A. When they were young, S0 galaxies used all their disk material and formed stars all in one burst
B. S0 galaxies are spirals that lost their dust and gas in a collision with hot intergalactic gas
C. S0 galaxies are spirals that lost their spiral arms because of their rapid rotation
D. All of the choices are viable explanations.
E. Only when they were young, S0 galaxies used all their disk material and formed stars all in one burst and S0 galaxies are spirals that lost their dust and gas in a collision with hot intergalactic gas are viable explanations.

61. Where do you expect to find an O type star?
A. In the halo of a spiral galaxy
B. Near the center of a small elliptical galaxy
C. On the disk of a large elliptical galaxy
D. On the spiral arms of a spiral galaxy
E. Equally likely in a spiral or elliptical galaxy

62. Which type of galaxy typically contains the least relative amount of gas and dust?
A. The spiral
B. The elliptical
C. The irregular
D. They all contain the same proportion.

63. Which type of galaxy often contains the largest relative amount of gas and dust?
A. The spiral
B. The elliptical
C. The irregular
D. They all contain about the same fraction.

64. Which of the following would explain the fact that elliptical galaxies contain mostly old stars?
A. Most of their gas is at low temperature.
B. Elliptical galaxies lack cool interstellar matter to form stars.
C. All the young stars are in dark molecular clouds, therefore invisible.
D. Most of the star-forming material in elliptical galaxies exists in the form of dark matter.

65. Which type of galaxy can have the largest mass?
A. A spiral galaxy
B. An elliptical galaxy
C. An irregular galaxy
D. An S0 galaxy

66. The majority of galaxies in our immediate vicinity (i.e., in the local group) are:
A. Large spiral galaxies.
B. Large elliptical galaxies.
C. Small spiral galaxies.
D. Irregular and small elliptical galaxies.
E. All kinds are equally likely.
Theres a fair amount of points in this section – don’t blow them off- you can do it, or at least try, what are you afraid of?

67.- 69. What evidence exists for the presence of a supermassive black hole at the center of our galaxy?

70. – 72. Give a possible explanation for the fact that galaxies with active nuclei are only located billions of light-years from us.

73.-75. Assuming that there was a tenth “planet” (yes, Pluto is no longer a “planet” but according to Bode’s law it is ) out beyond Pluto, that none-the-less could be predicted using Bode’s Law (SHOW ALL WORK! Anyone can do this!) Don’t forget Kepler’s third law!
a) how far would it be from the Sun? (you only need Bode’s law for this)
b) what would its orbital period be? (Kepler’s third law needed here)

76. – 80. Planet X is discovered circling a star 50 lt-yrs away from us. Analysis of the giant planet’s radius and mass, show them to be 1 x 10^10 centimeters (cm), (that’s ten to the tenth power – 10,000,000,000 – ten billion cm), and 6 x 10^27 grams a) What is the density of the giant planet ? (50% of the credit) density = mass/volume = 6 x 10^27/4.2 x10^27 = 1.4 g/cc b) would it be like a gas giant a terrestrial planet or what?

81. – 82. How long does it take sunlight to reach Pluto? (The inside front cover of your text has the distance) Show all work or no credit!

83. – 85. Calculate the density of Charon given the information on problem 8 p. 284. Show all work. What formulas would you need? To begin with, you’d want to calculate the volume – how? Then what?