Physics 014 The Astronomer s Universe Winter Midterm 1999 Instructor Brad Waugh Date February 17 1999 All answers should be written on the answer sheet provided You may keep the rest of the exam The test consists of 50 equally weighted multiple choice questions Q1 Compared to Jupiter Saturn shows less contrast in its band structure This is because 1 Saturn s atmosphere is of a more uniform chemical composition 2 Saturn has a weaker gravitational field and a thus a more distended series of cloud layers 3 Jupiter has a stronger magnetic field and correspondingly more energetic Van Allen belts 4 Saturn is further away from us and it is harder to discern the patterns Q2 The primary source of the energy radiated by Saturn is 1 The absorption and re radiation of solar radiation 2 The heat energy released at the point of formation of Saturn 3 The ongoing differentiation of droplets of helium 4 Metallic hydrogen Q3 Which gas giant has a rotational period greater than the Earth s 1 Jupiter 2 Neptune 3 All of them 4 None of them 1 Much more flattened 2 Much less flattened 3 About the same 4 Perfectly spherical Q4 If Jupiter had a composition similar to the Earth s its shape would be Q5 We infer that Saturn has a dense rocky core in part because Its shape doesn t show the degree of flattening it would have without such a core 1 2 Its shape shows more flattening than it would have without such a core 3 Seismographic studies show that P waves do not pass through the core 4 Seismographic studies show that S waves do not pass through the core Q6 Which of the following are not used to determine the various rotation rates of Jupiter 1 The periodicity of the radio signal from Jupiter s magnetosphere 2 The Doppler shift of spectral lines emitted by the atmosphere 3 The visual tracking of features in the upper clouds decks 4 The degree to which its shape is flattened Q7 At the Roche limit for a planet 1 The tidal forces due to the planet are equal to self gravitational forces of an orbiting body 2 All matter will be torn asunder by the overwhelming tidal force of the planet 3 There is a shepherding satellite moon in resonance with the planet s rings 4 None of the above Q8 The galilean satellites 1 Increase in density with increased distance from Jupiter 2 Decrease in density with increased distance from Jupiter 3 Are in retrograde orbit around Jupiter 4 Are probably captured from the asteroid belt Q9 The source of heat for Io s geological activity is 1 Radioactivity 2 Jupiter s magnetic field 3 Jupiter s tidal influence 4 The gravitational energy released by ongoing differentiation Q10 Europa may have the potential for evolving life because 1 2 3 4 It may have liquid oceans It has an atmosphere 60 more dense than the Earth s Its atmosphere is rich in organic molecules It has the greatest surface gravity of any planetary satellite Q11 Uranus and Neptune are 1 Similar in hydrogen and helium content but Neptune has proportionally more ammonia 2 Similar in hydrogen content but Uranus has proportionally more helium 3 Similar in helium content but Uranus has proportionally more hydrogen 4 Similar in hydrogen and helium content but Neptune has proportionally more methane Q12 Neptune shows more structure than Uranus in its clouds because 1 Neptune s cloud tops are 59 K and ammonia crystals form at 70 K 2 Uranus does not have an internal heat source to drive convective cells 3 Uranus has a much smaller gravitational field so its cloud levels are more spread out 4 Neptune is closer so the features are more easily discerned Q13 A Queen s grad student and a Queen s alumnus made the news in 1997 by discovering 1 Two new moons of Uranus 2 Neptune s moon Triton 3 The rings on Uranus 4 Neptune s internal heat source 1 Titan 2 Ganymede 3 Triton Q14 Which of the six large outer satellites is doomed to be torn apart to form a ring system Q15 Pluto is quite different from any of the other planets because of its 4 Callisto 1 Low density 2 High albedo 3 Large axial tilt 4 None of these Q16 Kirkwood gaps are caused by 1 Jupiter s periodic tugs on asteroids whose orbits are in resonance 2 The gravitational effects of Saturn s shepherd satellites 3 Cometary collisions 4 Jupiter s Lagrange points Q17 Which property of Pluto has yet to be determined 1 Mass 2 Strength of magnetic field 3 Size 4 Rotational period Q18 Uranus and Neptune differ from Jupiter and Saturn because Uranus and Neptune 1 Have magnetic fields tilted very far from the rotational axis and off centre 2 Are not massive enough to compress molecular hydrogen to its metallic form 3 Are so cold at their cloud tops that ammonia crystals form 4 All of these Q19 The Maunder minimum is 1 A region of the asteroid belt almost devoid of asteroids 2 The region of the Sun between the poles and 40 degrees latitude where sunspot activity virtually disappears 3 The lowest temperature at which fusion can occur 4 The period from 1645 to 1715 noted for very little sunspot activity Q20 The asteroids are 1 The remnants of a planet which was torn apart by the gravitational field of Jupiter 2 The remnants of a planet which was destroyed by a collision with a similar sized body 3 Material leftover from the era of planet formation inhibited from coalescing by Jupiter s 4 Material that once resided in Jupiter s Lagrange points knocked into a sunward orbit by gravitational field interactions with comets Q21 When a comet is near the Sun 1 The dust tail points directly away from the Sun 2 The ion tail points directly away from the Sun 3 The dust tail points directly toward the Sun 4 Both the dust and ion tail point directly away from the Sun Q22 Which of the following is NOT true for Kuiper belt comets 1 They are short period comets 2 Their orbits tend to lie close to the plane of the solar system 3 They originate in a belt just beyond the orbit of Neptune 4 They are the most common type of comet Q23 The extinction of the dinosaurs was caused by 1 A massive meteor shower 2 Comet Hale Bopp 3 The KT boundary event 4 The Tunguska explosion Q24 When a spinning cloud of gas and dust collapses it 1 Spins faster 2 Converts gravitational potential to kinetic energy 3 Tends to form a disk and a central ball of material 4 All of these Q25 In the condensation model of planetary formation how do dust particles first grow 1 By gravitational attraction and accumulation 2 By collision and sticking 3 By contracting and spinning faster 4 By molecular attraction Q26 Supergranules are 1 The tops of the