Test Bank to Accompany Astronomy: A Beginner’s Guide to the Universe Seventh Edition by Eric Chaisson and Steve McMillan Pearson Education, Inc © 2013 9/11/12 Contents Chapter 0 Charting the Heavens: The Foundations of Astronomy 1 Chapter 1 The Copernican Revolution: The Birth of Modern Science 18 Chapter 2 Light and Matter: The Inner Workings of the Cosmos 29 Chapter 3 Telescopes: The Tools of Astronomy 47 Chapter 4 The Solar System: Interplanetary Matter and the Birth of the Planets 62 Chapter 5 Earth and Its Moon: Our Cosmic Backyard 85 Chapter 6 The Terrestrial Planets: A Study in Contrasts 107 Chapter 7 The Jovian Planets: Giants of the Solar System 127 Chapter 8 Moons, Rings, and Plutoids: Small Worlds Among Giants 146 Chapter 9 The Sun: Our Parent Star 170 Chapter 10 Measuring the Stars: Giants, Dwarfs, and the Main Sequence 189 Chapter 11 The Interstellar Medium: Star Formation in the Milky Way . 212 Chapter 12 Stellar Evolution: The Lives and Deaths of Stars 233 Chapter 13 Neutron Stars and Black Holes: Strange States of Matter 259 Chapter 14 The Milky Way Galaxy: A Grand Design . 279 Chapter 15 Normal and Active Galaxies: Building Blocks of the Universe 304 Chapter 16 Galaxies and Dark Matter: The Large‐Scale Structure of the Cosmos 331 Chapter 17 Cosmology: The Big Bang and the Fate of the Universe 348 Chapter 18 Life in the Universe: Are We Alone? . 371 Chapter 0 Charting the Heavens: The Foundations of Astronomy 1) Right ascension in the sky is very similar to latitude on the Earth Answer: FALSE Diff: 1 Section Ref.: 0.1 2) Latitude and right ascension are coordinate systems used to find objects on the celestial sphere Answer: FALSE Diff: 1 Section Ref.: 0.1 3) The celestial sphere is divided into 88 modern constellations Answer: TRUE Diff: 1 Section Ref.: 0.1 4) In the sky, declination is measured in degrees north or south of the celestial equator Answer: TRUE Diff: 1 Section Ref.: 0.1 5) The south celestial pole is located at a declination of -90 degrees Answer: TRUE Diff: 1 Section Ref.: 0.1 6) In general, the brightest star in a given constellation is designated as alpha Answer: TRUE Diff: 1 Section Ref.: 0.1 7) Constellations are close clusters of stars, all at about the same distance from the Sun Answer: FALSE Diff: 1 Section Ref.: 0.1 8) The closest terrestrial analog to hours of right ascension is angle of longitude Answer: TRUE Diff: 2 Section Ref.: 0.1 9) Over 20,000 stars are visible to the naked eye on the darkest, clearest nights Answer: FALSE Diff: 2 Section Ref.: 0.1 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 10) A star with a right ascension of 2.6 hrs will rise 2.6 hours after the vernal equinox Answer: TRUE Diff: 3 Section Ref.: More Prec. 0.1 11) A tropical year is the same as a sidereal year Answer: FALSE Diff: 1 Section Ref.: 0.2 12) The sidereal day is determined by the Earthʹs rotation with respect to the stars Answer: TRUE Diff: 1 Section Ref.: 0.2 13) The vernal equinox marks the beginning of spring in the northern hemisphere Answer: TRUE Diff: 1 Section Ref.: 0.2 14) There are 3,600 arc seconds in a degree Answer: TRUE Diff: 2 Section Ref.: More Prec. 0.1 15) An hour of right ascension corresponds to 60 degrees in the sky Answer: FALSE Diff: 2 Section Ref.: 0.2 16) From Earth, the Sun and Moon have about the same angular diameter Answer: TRUE Diff: 1 Section Ref.: 0.2 17) At the solstices, the Sunʹs declination will be 23.5 degrees from the equator Answer: TRUE Diff: 2 Section Ref.: 0.2 18) At the equinoxes, the declination of the Sun must be zero degrees Answer: TRUE Diff: 2 Section Ref.: 0.2 Copyright © 2013 Pearson Education, Inc Chapter 0 Charting the Heavens 19) As it orbits the Earth, the Moon appears to move its own diameter (0.5 degrees) eastward every hour against the background stars Answer: TRUE Diff: 3 Section Ref.: 0.3 20) From full moon to third quarter moon takes about a week Answer: TRUE Diff: 1 Section Ref.: 0.3 21) Only people in the Moonʹs umbral shadow can see a total solar eclipse Answer: TRUE Diff: 1 Section Ref.: 0.3 22) If we are the Moonʹs penumbra, then we will see a partial lunar eclipse Answer: FALSE Diff: 1 Section Ref.: 0.3 23) There is a solar eclipse of some kind every new moon Answer: FALSE Diff: 1 Section Ref.: 0.3 24) Eighteen days past new moon, the Moonʹs phase is waning gibbous Answer: TRUE Diff: 2 Section Ref.: 0.3 25) A total solar eclipse will only occur when the new moon is both on the ecliptic and at its greatest distance from Earth Answer: FALSE Diff: 2 Section Ref.: 0.3 26) The larger the parallax shift, the closer an object is to us Answer: TRUE Diff: 1 Section Ref.: 0.4 27) The parallax shift for all stars is very small Answer: TRUE Diff: 1 Section Ref.: 0.4 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 28) Increasing the baseline will increase the parallax angle Answer: TRUE Diff: 3 Section Ref.: 0.4 29) In the scientific method, it is not necessary to test your theory Answer: FALSE Diff: 1 Section Ref.: 0.5 30) Drawing on Eratosthenesʹ method, if two observers are due north and south of each other and are separated by 400 km, what is the circumference of their spherical world if they see the same star on their meridian at altitudes of 23 degrees and 47 degrees respectively, and at the exact same time? A) 2,000 km B) 4,000 km C) 6,000 km D) 8,000 km E) 12,000 km Answer: C Diff: 3 Section Ref.: 0.4 31) The star Wolf 1061 has a parallax of 2.34 arc seconds, while the star Ross 652 has a parallax of 1.70 arc seconds. What can you correctly conclude? A) Both stars are outside the Milky Way galaxy B) Wolf 1061 must have a larger proper motion than Ross 652 C) Ross 652 must have a larger proper motion than Wolf 1061 D) Ross 652 is closer to Earth than Wolf 1061 E) Wolf 1061 is closer to Earth than Ross 652 Answer: E Diff: 2 Section Ref.: 0.4 32) The greatest distance above or below the ecliptic the Moon can move is A) 5.2 degrees B) 23.5 degrees C) 27.3 degrees D) 29.5 degrees E) 30 degrees Answer: A Diff: 3 Section Ref.: 0.3 Copyright © 2013 Pearson Education, Inc Chapter 0 Charting the Heavens 33) In an annular eclipse, A) the Sun is totally blocked by the Moon B) the Moon is totally blocked by the Earth C) the Moon appears as a thin, bright ring D) the Sun appears as a thin, bright ring E) the Sun is partially blocked by the Earth Answer: D Diff: 2 Section Ref.: 0.3 34) If you are in the Earthʹs umbra on the Earthʹs surface, then A) it must be a total solar eclipse B) it must be a lunar eclipse of some type C) it is night time D) the Sun is always visible E) the Moon is always visible Answer: C Diff: 2 Section Ref.: 0.3 35) The synodic month is A) 29.5 days B) about two days shorter than the sidereal month C) based on the Moonʹs position relative to the stars D) the basis of the year we use in our modern calendar E) caused by both the Earthʹs and Moonʹs rotations Answer: A Diff: 2 Section Ref.: 0.3 36) If the Moon appears half lit, and is almost overhead about 6:00 AM, its phase is A) waxing crescent B) first quarter C) full D) third quarter E) waning crescent Answer: D Diff: 2 Section Ref.: 0.3 37) If new moon fell on March 2nd, what is the Moonʹs phase on March 14th? A) waxing crescent B) first quarter C) waxing gibbous D) full E) waning crescent Answer: C Diff: 2 Section Ref.: 0.3 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 38) A solar eclipse can only happen during a A) new moon B) solstice C) first quarter moon D) full moon E) perihelion passage of the Sun Answer: A Diff: 2 Section Ref.: 0.3 39) What will occur when the full moon is on the ecliptic? A) a total lunar eclipse B) a total solar eclipse C) a partial solar eclipse D) an annular lunar eclipse E) a partial lunar eclipse if the Moon is at perigee Answer: A Diff: 1 Section Ref.: 0.3 40) If you are in the Moonʹs umbral shadow, then you are witnessing A) nighttime B) a total solar eclipse C) a total lunar eclipse D) a partial solar eclipse E) some kind of lunar eclipse Answer: B Diff: 1 Section Ref.: 0.3 41) The time for the Moon to orbit Earth, relative to the stars is A) 23 hours, 56 minutes B) about 7 days C) 27.3 days D) 29.5 days E) 18 years, 11.3 days Answer: C Diff: 1 Section Ref.: 0.3 42) The interval from new Moon to first quarter is about a(n) A) hour B) day C) week D) month E) year Answer: C Diff: 1 Section Ref.: 0.3 Copyright © 2013 Pearson Education, Inc Chapter 0 Charting the Heavens 43) The star Thuban in Draco A) lies as the center of the precession cycle B) was an excellent north pole star in 3,000 BC C) is brighter than Polaris D) lies halfway between the bowls of the Big and Little Dippers E) is used to locate the vernal equinox Answer: B Diff: 3 Section Ref.: 0.2 44) If Scorpius is now prominent in the summer sky, in 13,000 years it will be best seen A) at the same season; the heavens do not change B) in the autumn C) in the winter sky D) in the spring sky E) It will not be visible then at all. All of its stars will have vanished by then Answer: C Diff: 3 Section Ref.: 0.2 45) If Taurus is now rising at sunset, which constellation will rise at sunset next month? A) Scorpius B) Aquarius C) Gemini D) Aries E) Pisces Answer: C Diff: 3 Section Ref.: 0.2 46) The fact that the Earth has moved along its orbit in the time it took to rotate once is the reason for A) the difference between solar and sidereal time B) precession C) seasons D) the position of the Celestial Equator E) Earthʹs 23.5-degree tilt Answer: A Diff: 3 Section Ref.: 0.2 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 47) When the Moon is directly opposite the Sun in the sky, its phase is A) new B) waxing or waning crescent C) first or third quarter D) waxing or waning gibbous E) full Answer: E Diff: 2 Section Ref.: 0.2 48) You note that a particular star is directly overhead. It will be directly overhead again in A) 1 hour B) 12 hours C) 23 hours 56 minutes D) 24 hours E) 24 hours 4 minutes Answer: C Diff: 2 Section Ref.: 0.2 49) As you watch a star, you see it move 15 degrees across the sky. How long have you been watching it? A) 1 hour B) 3 hours C) 15 minutes D) 15 seconds E) 1 minute Answer: A Diff: 2 Section Ref.: 0.2 50) That Polaris will not always be the pole star is due to A) the sidereal day being shorter than the solar day B) precession shifting the celestial pole C) the Moon following the ecliptic, instead of the equator D) the Earthʹs revolution being slightly less than exactly 365.25 days E) the Solar winds blowing the Earth farther away from the Sun Answer: B Diff: 2 Section Ref.: 0.2 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 65) If the Moon rises at sunset, then its phase must be Answer: full Diff: 2 Section Ref.: 0.3 66) If the Moon is on the ecliptic, new, and at its farthest distance from Earth, we will get a(n) solar eclipse Answer: annular Diff: 2 Section Ref.: 0.3 67) Our seasons are a consequence of the Earthʹs 23.5 degree Answer: axial tilt Diff: 1 Section Ref.: 0.3 68) Over the course of the year, the Sunʹs noon altitude varies by degrees Answer: 47 Diff: 2 Section Ref.: 0.3 69) That we do not get eclipses every new and full Moon is due to the degree tilt of the Moonʹs orbit, relative to the ecliptic Answer: 5.2 (or just 5) Diff: 2 Section Ref.: 0.3 70) The apparent angular shift of any object across a distant background, when viewed from two different places, is called shift Answer: parallax or parallactic Diff: 1 Section Ref.: 0.4 71) Sirius has a parallax of 0.38ʺ, while Alpha Centauriʹs is 0.77.ʺ Alpha Centauri is about as Sirius Answer: twice as close, or half as far Diff: 1 Section Ref.: 0.4 72) If one star has a parallax ten times larger than anotherʹs, the first star is Answer: ten times closer than the second Diff: 1 Section Ref.: 0.4 73) If two observatories on opposite sides of the Earth were to measure the position of a star to calculate its parallax, then the diameter of the Earth would be the Answer: baseline Diff: 2 Section Ref.: 0.4 12 Copyright © 2013 Pearson Education, Inc Chapter 0 Charting the Heavens 74) One of the requirements of the Scientific Method is that an experiment must be Answer: repeatable Diff: 1 Section Ref.: 0.5 75) What do both latitude on Earth and declination in the sky measure? Answer: Angular distance in degrees above or below the geographical and celestial equators Diff: 1 Section Ref.: 0.1 76) How is right ascension similar to longitude on Earth? Answer: Both measure positions east or west from a fixed point; Greenwich on Earth, the vernal equinox in the sky Diff: 1 Section Ref.: 0.1 77) What are the minimum and maximum values for declination in the sky for both north and south? Answer: From the equator at 0 degrees, to +90 degrees for the north celestial pole, and down to -90 degrees for the south celestial pole Diff: 1 Section Ref.: 0.1 78) How are right ascension in the sky and longitude on Earth different? Answer: Right ascension is measured in units of time eastward from the vernal equinox, while longitude is measured in degrees east or west of the Greenwich meridian Diff: 2 Section Ref.: 0.1 79) Define the celestial sphere Answer: An imaginary hollow sphere, with Earth at its center, on which all the stars (and other celestial bodies) are fixed. As the sphere rotates around the Earth, the stars move across our sky Diff: 2 Section Ref.: 0.1 80) What are the minimum and maximum values for right ascension in the sky? Answer: From 0 to 24 hours, going eastward from the vernal equinox Diff: 2 Section Ref.: 0.1 81) Which is longer, the sidereal or solar day? By how much? Answer: The solar day is approximately four minutes longer than the sidereal day Diff: 1 Section Ref.: 0.2 13 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 82) At the solstice, what is the maximum angle the Sun can be above or below the equator? Answer: +23.5 degrees in summer and -23.5 degrees in winter Diff: 1 Section Ref.: 0.2 83) How far above or below the ecliptic can the Sun move? Answer: The Sun follows the ecliptic eastward across the sky, never leaving it Diff: 1 Section Ref.: 0.2 84) If intending to teach his students the constellations by season, why would an astronomy instructor be advised to always assign the stars in the current western sky at the beginning of each term? Answer: As the Earth revolves around the Sun, the Sun appears to move one degree eastward per day. These stars are, therefore, soon lost in the Sunʹs glare Diff: 2 Section Ref.: 0.2 85) Which star shows the least motion in the northern sky over the course of an hour? Answer: Polaris, the North Star, lies within a degree of the celestial pole, and does not move noticeably with the naked eye over an entire night Diff: 2 Section Ref.: 0.2 86) Pensacola, Florida lies at a latitude of 30 degrees north. Where is Polaris in its sky? Answer: 30 degrees high in the north Diff: 3 Section Ref.: 0.2 87) How far above or below the equator can the Sun appear to move? Why? Answer: The Earthʹs axial tilt means the Sunʹs declination can reach 23.5 degrees north or south of the equator at the solstices Diff: 1 Section Ref.: 0.3 88) What happens on or about March 20th, and what does the name signify? Answer: The vernal equinox, because the days and nights are approximately equal in length Diff: 1 Section Ref.: 0.3 89) Why are some solar eclipses total, and others annular? Answer: The Moonʹs orbit is not a perfect circle. When the Moon is closer to Earth, it is big enough to cover the Sun completely; when it is too far away it appears smaller, so a ring of sunlight is still seen Diff: 2 Section Ref.: 0.3 14 Copyright © 2013 Pearson Education, Inc Chapter 0 Charting the Heavens 90) What is the length of the sidereal month, and how is it determined? Answer: It takes 27.3 days for the Moon to revolve around us and return to the same position against the background of stars Diff: 2 Section Ref.: 0.3 91) How long does the synodic month take, and how it this observed? Answer: The phase cycle of the Moon takes 29.5 days to return to exactly the same phase Diff: 2 Section Ref.: 0.3 92) How far above and below the celestial equator can the Sun move? Answer: The Sun never appears more than 23.5 degrees above or the below the celestial equator Diff: 2 Section Ref.: 0.3 93) The first quarter moon rises about noon today; what will its phase be, and when will it rise tomorrow? Answer: It will be waxing gibbous, and rise about 1 PM by the next day Diff: 2 Section Ref.: 0.3 94) The last quarter moon rises tonight about midnight; when will it rise, and what will its phase be tomorrow night? Answer: It will rise about an hour later, about 1 AM, and be a waning crescent by then Diff: 2 Section Ref.: 0.3 95) If the Moon rises exactly at sunset, what will its phase be? Why? Answer: The phase will be full because it is rising opposite the Sun Diff: 2 Section Ref.: 0.3 96) Why is Polaris not always the pole star, and when does it get another chance? Answer: Precession of the Earthʹs axis of rotation takes around 26,000 years Diff: 3 Section Ref.: 0.3 97) If Sirius transits my local meridian tonight at 6:43 PM, when will it transit tomorrow? Answer: At 6:39 PM tomorrow night, as the Earth spins once in a sidereal day Diff: 3 Section Ref.: 0.3 15 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 98) Compare and contrast latitude and declination. How does each relate to your position on Earth? Answer: Both are measured in degrees north or south of the equator, and are used to find positions on the Earth or in the sky. If you are at latitude 30 degrees north, then the stars that pass through your zenith (directly overhead) will have a corresponding declination of +30 degrees Diff: 2 Section Ref.: 0.1 99) Compare and contrast longitude and right ascension Answer: Longitude is measured in degrees both east and west of the Greenwich meridian, but right ascension is measured in units of time as the Earth rotates, and goes only eastward from the vernal equinox Diff: 3 Section Ref.: 0.1 100) Compare hours of right ascension to time zones on the Earth Answer: Like time zones, hours of right ascension are 15 degrees wide, and they run eastward across the sky from the Vernal Equinox, much like the time zones originate from the Prime Meridian Diff: 3 Section Ref.: 0.1 101) The Sun and stars rise in the east, and set in the west. Contrast ancient and modern explanations for this observation Answer: The ancients thought there was a vast celestial sphere, spinning over our heads once a day, and that the stars, Sun, Moon, and planets are all carried along for the ride. We now recognize it is the Earth itself that rotates eastward, creating this apparent westward motion of celestial bodies Diff: 2 Section Ref.: 0.2 102) Contrast the sidereal and solar days Answer: The Earth rotates once on its axis every 23 hours, 56 minutes, and thus turns to face the same distant star in that interval. But we are also revolving around the Sun at one degree eastward per day, hence the Sun appears to have moved eastward from one day to the next, and it takes a full 24 hours to align with the Sun again Diff: 2 Section Ref.: 0.2 103) Why can many more people witness a total lunar eclipse than a total solar eclipse? Answer: For a total solar eclipse to be seen, the observer must be in the Moonʹs umbra, a shadow only about a hundred miles across, while everyone on the night side of the Earth can look up to witness the full moon moving though our shadow Diff: 2 Section Ref.: 0.3 16 Copyright © 2013 Pearson Education, Inc Chapter 0 Charting the Heavens 104) What conditions are necessary for a total solar eclipse? Answer: The Moon must be at new phase (directly between Earth and the Sun), it must also be both at the closer distance in its orbit and on the ecliptic (crossing a node). Only people on those parts of the Earth where the Moonʹs umbral shadow passes will see a total solar eclipse Diff: 2 Section Ref.: 0.3 105) What is the astronomical significance of 26,000 years? Answer: The Earthʹs rotational axis itself rotates over this precession cycle, which also changes the location of the poles, equinoxes, and solstices in the sky Diff: 2 Section Ref.: 0.3 106) Describe how Eratosthenes measured the circumference of our planet Answer: Using the fact that the noon solstice Sun was directly overhead at Syene, on the Tropic of Cancer, yet was 7 degrees south of the zenith in Alexandria, Eratosthenes realized this was due to the curvature of the Earth, and that the 7 degrees was about 1/50th of the Earthʹs total circumference, so the Earth must be about fifty times larger in circumference than the 800 kilometer separation between Alexandria and Syene, or about 40,000 kilometers around Diff: 3 Section Ref.: 0.3 107) Which is longer, the sidereal or synodic month? Why? Answer: The synodic month takes an extra two days, because the Earth is also revolving around the Sun, so after 27.3 days the Moon returns to the same place among the stars, but the Earth has revolved about 27 degrees ahead of where it was last month; it takes the Moon two days to catch up to us Diff: 3 Section Ref.: 0.3 108) We get a new and full moon every month. Why donʹt we get two eclipses every month? Answer: The Moonʹs orbit is tilted 5.2 degrees to the Earthʹs orbit (the ecliptic), and the disks of the Sun and Moon are only about .5 degrees wide. Most months the new and full moon pass too far from the ecliptic for the Earthʹs and Moonʹs shadows to make eclipses occur Diff: 3 Section Ref.: 0.3 17 Copyright © 2013 Pearson Education, Inc Chapter 1 The Copernican Revolution: The Birth of Modern Science 1) According to Newtonʹs third law, when the Voyager probes passed Jupiter in 1979, they exerted exactly the same force on Jupiter as the giant planet did on them Answer: TRUE Diff: 3 Section Ref.: 1.4 2) Compared to when it was on the surface, a satellite in an orbit whose radius is about 4 times the Earthʹs radius will experience about 1/16 the force due to the Earthʹs gravity Answer: TRUE Diff: 3 Section Ref.: 1.4 3) According to Newtonʹs second law, if you double the force acting on a body, the acceleration will double Answer: TRUE Diff: 2 Section Ref.: 1.4 4) According to Newtonʹs first law, an object traveling in a circle does not have a force acting on it Answer: FALSE Diff: 1 Section Ref.: 1.4 5) Keplerʹs third law allows us to find the average distance to a planet from observing its period of rotation on its axis Answer: FALSE Diff: 2 Section Ref.: 1.3 6) According to Keplerʹs third law, if you know the planetʹs orbital period, you can find its average distance from the Sun Answer: TRUE Diff: 2 Section Ref.: 1.3 7) A planet (or comet) will speed up as it approaches the Sun Answer: TRUE Diff: 2 Section Ref.: 1.3 18 Copyright © 2013 Pearson Education, Inc Chapter 1 The Copernican Revolution: The Birth of Modern Science 8) Kepler found the orbits of planets are ellipses, not circles Answer: TRUE Diff: 1 Section Ref.: 1.3 9) Kepler relied heavily on the telescopic observations of Galileo in developing his laws of planetary motion Answer: FALSE Diff: 2 Section Ref.: 1.3 10) Keplerʹs third law relates the square of the planetʹs orbital period in years to the cube of its average distance from the Sun in astronomical units Answer: TRUE Diff: 1 Section Ref.: 1.3 11) Among Galileoʹs discoveries with his telescope were sunspots Answer: TRUE Diff: 1 Section Ref.: 1.2 12) Galileoʹs observations of the entire phase cycle of Venus proved that Ptolemyʹs epicycles could not be correct in keeping Venus between us and the Sun Answer: TRUE Diff: 1 Section Ref.: 1.2 13) According to Copernicus, retrograde motion occurs at opposition for the outer planets Answer: TRUE Diff: 2 Section Ref.: 1.1 14) In Ptolemyʹs geocentric model, the planetʹs motion along its deferent is all that is needed to understand retrograde motion Answer: FALSE Diff: 1 Section Ref.: 1.1 15) Copernicus believed the Earth was the center of all celestial motion Answer: FALSE Diff: 1 Section Ref.: 1.1 19 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 16) In Ptolemyʹs geocentric model, retrograde motion occurs when the planet is closest to us, on the inside portion of the A) deferent B) ellipse C) epicycle D) equant E) ecliptic Answer: C Diff: 1 Section Ref.: 1.1 17) In Ptolemyʹs geocentric model, the normal eastward motion of the planets was along A) a deferent B) an epicycle C) a retrograde loop D) an ellipse E) the equant Answer: A Diff: 1 Section Ref.: 1.1 18) Copernicusʹ Heliocentric theory explains that A) planetary orbits are elliptical in shape B) the Sun lies at one focus of an ellipse C) Venus retrogrades when she overtakes us at inferior conjunction D) all planets lie between the Sun and Earth E) Mars will retrograde when it reaches a certain position on its epicycle Answer: C Diff: 2 Section Ref.: 1.1 19) According to Copernicus, retrograde motion for Venus must occur around A) inferior conjunction, when it passes between us and the Sun B) quadrature, when the planet is 90 degrees away from the Sun C) greatest elongation, when the planet is farthest from the Sun D) superior conjunction, when the planet is on the far side of the Sun E) opposition, when the planet lies opposite the Sun in the sky Answer: A Diff: 2 Section Ref.: 1.1 20 Copyright © 2013 Pearson Education, Inc Chapter 1 The Copernican Revolution: The Birth of Modern Science 20) According to Copernicus, the retrograde motion for Mars must occur A) at inferior conjunction, when Mars laps the Earth and passes between us and the Sun B) at superior conjunction, when Mars lies on the far side of the Sun C) at quadrature, when Mars lies exactly 90 degrees east or west of the Sun D) at greatest elongation, when Mars can get up to 47 degrees from the Sun E) at opposition, when the Earth overtakes Mars and passes between Mars and the Sun Answer: E Diff: 2 Section Ref.: 1.1 21) A fatal flaw with Ptolemyʹs model is its inability to predict the observed phases of A) the Sun during an eclipse B) the Moon in its monthly cycle C) Mercury and Venus D) Mars and Jupiter E) Jupiter and Saturn Answer: C Diff: 2 Section Ref.: 1.2 22) Which of these was NOT seen telescopically by Galileo? A) sunspots B) Venusʹ phase cycle C) Four moons around Jupiter D) stellar parallax E) craters and mare on the Moon Answer: D Diff: 1 Section Ref.: 1.2 23) Which of these observations of Galileo refuted Ptolemyʹs epicycles? A) the complete cycle of Venusʹ phases B) the rotation of sunspots across the Sunʹs surface C) the revolution of Jupiterʹs moons around it D) the craters on the Moon E) the visibility of many more stars with the telescope Answer: A Diff: 2 Section Ref.: 1.2 24) Galileo found the rotation period of the Sun was approximately A) a day B) a week C) a month D) three months E) a year Answer: C Diff: 3 Section Ref.: 1.2 21 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 25) Tycho Braheʹs contribution to Keplerʹs Laws of Planetary Motion were A) his detailed and accurate observations of the planetsʹ positions B) his observations of Jupiterʹs moons C) a mathematical explanation of epicycles D) a precise lunar calendar E) the correct explanation of lunar phases Answer: A Diff: 1 Section Ref.: 1.3 26) Keplerʹs first law worked, where Copernicusʹ original heliocentric model failed, because Kepler described the orbits as A) elliptical, not circular B) much larger than Copernicus had envisioned C) around the Sun, not the Earth D) being on equants instead of epicycles E) complex, with epicycles to account for retrograde motions Answer: A Diff: 1 Section Ref.: 1.3 27) When a planetʹs orbit takes it closest to the Sun, itʹs called A) vernal equinox B) aphelion C) perihelion D) crossing the ecliptic E) none of these; a planetʹs distance from the Sun never changes Answer: C Diff: 2 Section Ref.: 1.3 28) A planet whose distance from the Sun is 3 AU would have an orbital period of how many Earth-years? A) B) 27 C) D) E) 81 Answer: B Diff: 3 Section Ref.: 1.3 22 Copyright © 2013 Pearson Education, Inc Chapter 1 The Copernican Revolution: The Birth of Modern Science 29) The force of gravity varies with the A) product of the two masses B) inverse of the distance separating the two bodies C) inverse square of the distance separating the two bodies D) Both A and B are correct E) Both A and C are correct Answer: E Diff: 1 Section Ref.: 1.4 30) A circular orbit would have an eccentricity of A) B) between 0 and 0.5 C) between 0.5 and 1 D) exactly 1.0 E) infinity Answer: A Diff: 1 Section Ref.: 1.4 31) How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it is on Saturn at 10 AU? A) B) 10 C) 25 D) 100 E) 250 Answer: D Diff: 3 Section Ref.: 1.4 32) If the distance between two asteroids is doubled, the gravitational force they exert on each other will A) also be doubled B) be half as great C) be one fourth as great D) will be 1/16 as great E) be four times greater Answer: C Diff: 3 Section Ref.: 1.4 33) Because he failed to observe stellar , Aristotle wrongly concluded we could not be in orbit around the Sun Answer: parallax Diff: 1 Section Ref.: 1.1 23 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 34) The mean distance between the Earth and Sun is called the Answer: astronomical unit Diff: 1 Section Ref.: 1.1 35) Ptolemyʹs model was , with the Earth fixed in the center of the universe Answer: geocentric Diff: 1 Section Ref.: 1.1 36) The model of used circular deferents and epicycles in a geocentric universe to explain planetary motions Answer: Ptolemy Diff: 1 Section Ref.: 1.1 37) The time for a planet to revolve around the Sun is its Answer: orbital period or year Diff: 2 Section Ref.: 1.1 38) When Earth overtakes Mars, the outer planet retrogrades near Answer: opposition Diff: 2 Section Ref.: 1.1 39) The ʺguest starʺ observed by the Chinese in 1054 is now known to have been a Answer: supernova Diff: 2 Section Ref.: 1.1 40) Galileoʹs discovery of four moons orbiting provided new support for the ideas of Copernicus Answer: Jupiter Diff: 2 Section Ref.: 1.2 41) For Galileo, the observation of the phases of proved that Ptolemyʹs geocentric model with epicycles was wrong Answer: Venus Diff: 2 Section Ref.: 1.2 42) The hypothesis is that the Earth does not occupy any special place in the universe Answer: Copernican Diff: 3 Section Ref.: 1.2 24 Copyright © 2013 Pearson Education, Inc Chapter 1 The Copernican Revolution: The Birth of Modern Science 43) The three laws of planetary motion by allowed us to predict planetary motion Answer: Kepler Diff: 1 Section Ref.: 1.3 44) While both Ptolemy and Copernicus assumed all orbits were , Keplerʹs first law corrected this and made planetary motion predictable Answer: circles Diff: 1 Section Ref.: 1.3 45) Keplerʹs theories were based on the very accurate observations made by Answer: Tycho Brahe Diff: 2 Section Ref.: 1.3 46) According to Newtonʹs laws, the planets orbit the Sun due to Answer: gravity Diff: 1 Section Ref.: 1.4 47) According to Newton, the gravity of the is needed to explain planetary orbits Answer: Sun Diff: 1 Section Ref.: 1.4 48) In Newtonʹs first law, the of a body causes it to resist changes in its motion Answer: inertia Diff: 1 Section Ref.: 1.4 49) According to Newtonʹs second law, when the same force acts on two bodies, the body with the larger mass will have the acceleration Answer: smaller Diff: 1 Section Ref.: 1.4 50) Newton found that gravity varied with the of the distance between the two bodies pulling on each other Answer: inverse square Diff: 2 Section Ref.: 1.4 51) How did Ptolemy explain the retrograde motion of Venus? Answer: The epicycle for both Mercury and Venus is always centered on the Earth -Sun line, so they always orbit between us and the Sun Diff: 3 Section Ref.: 1.1 25 Copyright © 2013 Pearson Education, Inc Astronomy: A Beginnerʹs Guide to the Universe, 7th ed 52) How did Ptolemy explain the retrograde motion of Mars? Answer: Mars will retrograde on the inner portion of its epicycle, when it is closest to us and its motion on the epicycle is more obvious than its motion along its deferent Diff: 3 Section Ref.: 1.1 53) What ʺimperfectionsʺ on the Moon were visible to Galileoʹs telescopes? Answer: Impact craters, mountains, and dark lava flows, or mare Diff: 2 Section Ref.: 1.2 54) What is meant by the astronomical unit? Answer: The astronomical unit, or AU, is the mean distance between the Earth and Sun Diff: 2 Section Ref.: 1.2 55) How did Tychoʹs detailed observations of Marsʹ brightness help show that its orbit could not be circular? Answer: Tycho noted that at some oppositions, Mars was much brighter than at others, suggesting that Mars must be closer to us when it was brighter Diff: 3 Section Ref.: 1.1 56) What did Galileo discover through his telescope when he looked at Jupiter, and how did it refute the Ptolemaic model? Answer: That Jupiter had four moons in orbit about it, so Earth was not the center of all things Ptolemy contended that all things move around the Earth Diff: 3 Section Ref.: 1.2 57) The speed of light (and radio waves) is 300,000 km/s. How far away is a spacecraft if its radio signal takes 10 minutes to reach Earth? Answer: 180,000,000 km Diff: 3 Section Ref.: 1.2 58) What did Galileo discover when looking at the Sun with his telescope, and how did this support Copernicus? Answer: Sunspots, which rotated across the Sunʹs face, showing that the Sun was not perfect and it (and Earth) could rotate on its axis Diff: 3 Section Ref.: 1.2 59) Explain how the eccentricity describes the shape of an ellipse Answer: The higher the eccentricity, the more elongated the oval; a circle has an eccentricity of zero, while very stretched-out comet orbits approach an eccentricity of one Diff: 3 Section Ref.: 1.3 26 Copyright © 2013 Pearson Education, Inc ... What will occur when the full moon is on the ecliptic? A) a total lunar eclipse B) a total solar eclipse C) a partial solar eclipse D) an annular lunar eclipse E) a partial lunar eclipse if the Moon is at perigee... The star Wolf 1061 has a parallax of 2.34 arc seconds, while the star Ross 652 has a parallax of 1.70 arc seconds. What can you correctly conclude? A) Both stars are outside the Milky Way galaxy... This diagram explains A) the difference between solar time and sidereal time B) precession C) the solar dayʹs relation to the Moon D) the sidereal dayʹs relation to the seasons E) the reason for the solstices