Astronomy Ch. 6 The Solar System: Comparative Planetology

Name: Period: Date: Astronomy Ch. 6 The Solar System: Comparative Planetology MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The largest asteroid, and probably the only one to be a spherical "world" is A) Ida. B) Gaspra. C) Ceres. D) Vesta. E) Eros. 1) 2) Which planet by itself contains the majority of mass of all the planets? A) the earth B) Saturn C) Venus D) Jupiter E) Uranus 2) 3) Our understanding of the solar system has come in a way that can best be described as: A) erratic, with spurts when new planets were found. B) steady until the last decade, when the decline in the space program slowed it a great deal. C) explosive, with us learning more in the past few decades than in all previous history. D) slow and steady since the discovery of the telescope by Galileo. E) constant since prehistoric times. 3) 4) What is the goal of comparative planetology? A) to find out how our own solar system compares with extrasolar ones B) to help plan future visits by unmanned probes, orbiters, and rovers C) to use planetary positions to foretell the future D) to find which planets will be most suitable for future colonization E) to determine the origin and evolution of the solar system 4) 5) What is true about solar system densities? A) Saturn has the same density as water. B) The denser planets lie closer to the Sun. C) The asteroids all have about the same density. D) In differentiated bodies, the denser materials lie near their surfaces. E) Planetary density increases with increasing distance from the Sun. 5) 6) The planet's orbital period is: A) the time it takes for a satellite to orbit it. B) the time it takes to return to the same location in the sky, relative to the Sun. C) the time it takes for it to retrograde back to the same position as we pass it. D) the time it takes it to rotate and have the same face toward us again. E) the time its magnetic field takes to spin once. 6) 7) Masses of the planets are easiest to determine if: A) they have natural satellites whose motions can be precisely measured. B) they are dense and easily deflect the path of passing spacecraft. C) they are terrestrial and the extra size of the planet's disk can be measured. D) they move rapidly and their periods are easily measured. E) they are jovian and their oblateness can be found. 7) 1

8) The average density of each planet in the solar system is determined by taking its mass and dividing that by its A) radius squared B) volume C) diameter D) radius E) surface area 8) 9) Which of these bodies has the lowest density? A) an asteroid B) a comet C) Saturn D) Jupiter E) Kuiper Belt objects 9) 10) The rotation periods of Venus, Jupiter, Saturn, Uranus and Neptune are difficult to determine because A) their surface features are obscured by their atmospheres. B) they rotate so fast. C) they are all gas giants. D) each one has a large satellite that interferes with this measurement. E) they are so far away from the Sun. 10) 11) In order to determine the mass of a planet by applying Newton's laws of motion and gravity, the planet must have A) a solid surface. B) moons. C) planets further from the Sun than itself. D) rings. E) a known size and distance from Earth. 11) 12) The plane in which almost all planets orbit the sun is called the: A) equant. B) ecliptic. C) galactic plane. D) node. E) equator of the solar system. 12) 13) Which statement about the motion of the planets is incorrect? A) Most planets move in the Earth's equatorial plane. B) All revolutions of major planets are counterclockwise. C) The orbits of most planets are almost circular, with low eccentricities. D) Most planets rotate in the counterclockwise direction when viewed from the North. E) Most orbit above the Sun's equator. 13) 2

14) Mercury's most unusual orbital feature, as compared to the other planets, is A) the size of the planet. B) its orbital period. C) that it has no moons. D) the size of its orbit. E) the shape of its orbit. 14) 15) What aspects of the planets orbits are nearly the same for most planets? A) tilt from the ecliptic and distance from the Sun B) shape and tilt from the ecliptic C) shape and distance from the Sun D) orbital period and shape E) orbital period and distance from the Sun 15) 16) Planetary orbits A) are evenly spaced throughout the solar system. B) are spaced more closely together as they get further from the Sun. C) are almost circular, with low eccentricities. D) have the Sun at their exact center. E) are highly inclined to the ecliptic. 16) 17) How do the densities of the jovian and terrestrial planets compare? A) More massive jovians all have high densities, compared to the tiny terrestrials. B) Made from the same solar nebula, they are all similar. C) The closer a planet lies to the Sun, the less its density. D) All terrestrials are more dense than any of the jovians. E) No real pattern here; densities vary greatly and are very individual to each world. 17) 18) Which of the following are the Jovian planets? A) everything past Mars and the asteroid belt B) only Jupiter and Saturn C) Jupiter, Saturn, Uranus, and Neptune only D) Jupiter, Saturn, Uranus, Neptune, and Pluto E) only Jupiter 18) 19) In composition and mass and density, Jupiter is most like: A) a huge comet. B) a huge Kuiper belt Object. C) a gigantic asteroid. D) a large terrestrial planet. E) the Sun. 19) 20) Which characteristic listed below describes the jovian planets? A) solid surfaces B) small masses C) low density D) close to the Sun E) slow rotational period 20) 3

21) Which of the characteristics below describes the terrestrial planets? A) large and gaseous B) widely spaced through the outer solar system C) possessing weak magnetic fields D) having rings E) small, dark and icy 21) 22) The jovian planets A) all lie less than 5 AU from the Sun. B) are all much more dense than any of the terrestrials planets. C) all have rings around their equators. D) have satellite systems with less than 4 moons. E) all spin slower than the earth. 22) 23) Most asteroids are found: A) in the orbit of Jupiter, but 60 degrees ahead or behind it. B) orbiting the jovian planets in captured, retrograde orbits. C) beyond the orbit of Neptune. D) between the orbits of Mars and Jupiter. E) between the Earth and Sun. 23) 24) The Kuiper Belt is found where in the solar system? A) between the orbits of Jupiter and Uranus B) sixty degrees ahead or behind Jupiter C) beyond the orbit of Neptune D) among the orbits of the terrestrial planets E) between the orbits of Mars and Jupiter 24) 25) In composition and density, the asteroids most resemble: A) comets. B) pieces of terrestrial planets. C) Kuiper Belt objects like Pluto. D) jovian moons. E) the Sun. 25) 26) In composition, asteroids and meteoroids are most like A) jovian planets. B) Kuiper Belt objects. C) comets. D) terrestrial planets. E) the moons of Jupiter. 26) 27) The difference between a meteoroid and an asteroid is the object's A) shape. B) size. C) orbital period. D) location in the solar system. E) composition. 27) 4

28) The smallest sort of interplanetary matter is called A) a meteoroid. B) an asteroid. C) a comet. D) interplanetary dust. E) a Kuiper Belt Object. 28) 29) Which of the following is not icy in composition? A) the polar cap of Mars B) comet nuclei C) asteroids D) most Jovian satellites E) Kuiper Belt Objects 29) 30) The most detailed look we've had of an asteroid comes from A) ground based optical images.. B) high-altitude UV spectroscopy. C) spacecraft sent to an asteroid. D) ground based radar images. E) Earth orbital X-ray images. 30) 31) The Kuiper Belt is an "outer asteroid belt" consisting of what types of solar system bodies? A) meteoroids B) jovian planets C) terrestrial planets D) icy cometlike bodies E) asteroids 31) 32) Which of the following have an icy composition? A) comets B) meteorites and most asteroids C) most asteroids D) the surface of Mars E) meteoroids 32) 33) A meteorite is A) a streak of light in the atmosphere. B) a chunk of space debris orbiting the Earth. C) a chunk of space debris that has struck the ground. D) an icy body with a long tail extending from it. E) an irregularly shaped body, mostly found orbiting between Mars and Jupiter. 33) 34) Objects in the Kuiper belt A) are in random orbits at all inclinations to the ecliptic. B) lie beyond the orbit of Neptune, and close to the ecliptic. C) lie beyond the orbit of Neptune and perpendicular to the ecliptic.. D) are dense, like the iron meteorites. E) are the sources of long-period comets. 34) 5

35) Which of the following is considered "interplanetary matter"? A) Ganymede B) Titan C) the Moon D) Comet Hale-Bopp E) Triton 35) 36) The tail of a comet always points A) away from the Sun and becomes longest and brightest at perihelion. B) in the direction of the comet's motion. C) toward Earth and never varies. D) toward the Sun and disappears at perihelion. E) away from the Sun and disappears at perihelion. 36) 37) A gravitational "sling-shot": A) allowed the Apollo astronauts to reach the Moon in 1969. B) causes comets to crash into planets, such as Jupiter in 1994. C) explains how the solar system was formed after a near collision with another star. D) changes the speed and direction of a spacecraft nearing a massive planet. E) is the accepted theory for the formation of the asteroid belt. 37) 38) Which of these spacecraft went into orbit about Saturn in July 2004? A) Galileo B) NEAR-Shoemaker C) Voyager 2 D) Cassini E) New Horizons 38) 39) Which spacecraft gave us our best information about Mercury, until Messenger arrives in 2009? A) Mariner 10 B) Pioneer 10 C) Viking 2 D) Voyager I E) No spacecraft can withstand the great heat that close to the Sun. 39) 40) The best present maps of the surface of Venus come from the: A) Messenger orbiter. B) Venera 14 lander. C) Global Surveyor. D) Magellan. E) Venera 15 orbiter. 40) 41) The only spacecraft to be intentionally crashed into Jupiter was: A) Magellan. B) Voyager 1. C) Cassini. D) Pioneer 11. E) Galileo. 41) 6

42) The "Grand Tour" of all four jovians was conducted by: A) Cassini. B) Voyager 1 and 2 both. C) Galileo. D) Pioneer 11. E) Voyager 2. 42) 43) Our best close-up views of the jovian moons came from the many passes by: A) New Horizons. B) Cassini. C) Global Surveyor. D) Voyager 2. E) Galileo. 43) 44) The Mariner 10 spacecraft visited which bodies in the solar system? A) Mars and Mercury B) Venus and Mars C) the jovian planets D) Mercury and Venus E) Mars and Jupiter 44) 45) While Cassini was launched toward Saturn in 2004, its Huygens probe in 2005 went to: A) Jupiter. B) Saturn's polar regions. C) Titan. D) Uranus. E) Pluto. 45) 46) Which objects in the solar system have been least modified since the formation of the solar system? A) jovian moons B) asteroids C) Kuiper Belt objects D) meteoroids E) terrestrial planets 46) 47) Which of these was the first to cross the asteroid belt and head to Jupiter? A) Galileo B) Cassini C) Mariner 10 D) Voyager I E) Pioneer 10 47) 48) Which statement about Mercury is not correct? A) Mariner 10 is now dead, but still in orbit about Mercury. B) It is the target for planned orbiters from NASA, Japan, and the ESA. C) Mariner 10 revealed its cratered surface looking much like our Moon. D) About half of its surface was mapped by Mariner 10. E) Mariner 10 needed a gravity assist from Venus to get to it in 1974. 48) 7

49) Which of these landed on Venus? A) Surveyor 7 B) Viking 2 C) NEAR-Shoemaker D) Rover Spirit E) Venera 7 49) 50) As the solar nebula contracts due to gravitation, the cloud A) becomes more spherical in shape. B) spins faster. C) changes direction of motion. D) begins to cool. E) expands. 50) 51) What is the name of the theory that is currently used to describe the formation of the solar system? A) Perturbation Theory B) Nebular theory C) Close-encounter theory D) Condensation theory E) Differentiation Theory 51) 52) The Kuiper Belt is found where in the solar system? A) among the orbits of the terrestrial planets B) beyond the orbit of Neptune C) between the orbits of Jupiter and Uranus D) sixty degrees ahead or behind Jupiter E) between the orbits of Mars and Jupiter 52) 53) What is the role of irregularities in the solar system in terms of theories of its origin? A) Theories of the solar system are entirely based on the many irregularities found among the planets and moons. B) The solar system is chaotic, with irregularities the rule. C) They introduce a need for flexibility in theories of the solar system's origin. D) The solar system has no irregularities; it is perfectly regular and orderly. E) They are too minor to play a role; astronomers ignore them. 53) 54) Which of these is not a characteristic of the solar nebula theory? A) Larger planets should form closer to their star, where there is more debris. B) Planets should rotate counterclockwise as well. C) All the planets should follow the ecliptic plane. D) All the planets should orbit the sun counterclockwise. E) The ecliptic is the equator for the Sun. 54) 55) What might have made the original solar nebula begin to contract? A) the large amount of angular momentum in the nebula B) the shock wave from a nearby exploding star C) the Big Bang D) interstellar magnetism generated by pulsars E) the formation of our arm of the Milky Way 55) 8

56) The meteorites that strike Earth are A) material from outside our solar system. B) the oldest rocks known. C) the remains of the planet between Mars and Jupiter. D) pieces of comets that fall to Earth. E) mostly made of iron. 56) 57) A successful theory of the formation of the solar system must explain A) that all planets have elliptical orbits with high eccentricities. B) that all planets rotate in a prograde sense. C) all observed properties of the solar system. D) the existence of the asteroid belt between Jupiter and Neptune. E) that the inner planets have more hydrogen and helium in their atmospheres than do the outer planets. 57) 58) Planetary orbits A) are highly inclined to the ecliptic. B) are evenly spaced throughout the solar system. C) are almost circular, with low eccentricities. D) have the Sun at their exact center. E) are spaced more closely together as they get further from the Sun. 58) 59) What is true about solar system densities? A) The denser planets lie closer to the Sun. B) Saturn has the same density as water. C) The asteroids all have about the same density. D) In differentiated bodies, the denser materials lie near their surfaces. E) Planetary density increases with increasing distance from the Sun. 59) 60) The jovian planets A) have satellite systems with less than 4 moons. B) all have rings around their equators. C) all spin slower than the earth. D) all lie less than 5 AU from the Sun. E) are all much more dense than any of the terrestrials planets. 60) 61) What phase of planet formation caused the jovian planets to form? A) core-accretion B) fragmentation C) collision D) differentiation E) condensation 61) 62) What happens when a solar nebula contracts? A) It spins faster. B) It flattens out. C) It heats up. D) all of the above E) none of the above 62) 9

63) In light of modern solar system theory, why do the orbits of the planets all lie in the same plane? A) This happened purely by chance. B) Comets would have wiped out any not in this protected plane. C) The early solar nebula flattened into a disk. D) The Sun's gravity forced them into these orbits. E) The angular momentum of the solar system was kept to a minimum this way. 63) 64) What is the process of accretion? A) the separation of materials in a protoplanet by density, with dense material in core B) the process by which the solar nebula became heated during its collapse C) growth of an object by the accumulation of matter D) the breakup of large objects by violent collisions with other similar-sized objects E) the period of time during which the Sun swept away all the excess material in the solar nebula 64) 65) Conservation of angular momentum means that a spinning body tends to A) keep spinning. B) fly apart. C) gravitationally collapse. D) slow down. E) wobble into an eccentric orbit. 65) 66) Dust is an important part of the nebular theory of solar system formation because dust is needed to explain A) how the outer planets came to be gaseous bodies. B) how the initial cloud heated as it contracted. C) why the icy bodies are located so far from the Sun. D) how the initial cloud cooled enough to collapse. E) how the inner planets came to be rocky bodies. 66) 67) What factor caused different planets to form out of different types of material? A) The angular momentum of the forming planet; faster rotating planets lost the lightest elements. B) The angular momentum of the solar nebula pushed the heavy elements towards the outer regions of the nebula. C) The quantity of dust particles in the solar nebula; more dust caused some planets to contain heavier elements. D) The innate variation of chemical composition of the original nebula; the outer parts of the nebula contained a greater abundance of heavy elements. E) The variation in temperature throughout the solar nebula; the higher the temperature, the lower the percentage of light elements in the forming planet. 67) 68) What was the primary role of dust in the formation of the solar system? A) Dust acted as condensation nuclei; platforms to which other particles could attach and form larger particles of matter. B) Dust veiled the process by which our solar system formed. C) The Sun formed from a vast spinning cloud consisting only of dust. D) Dust formed the rings around Uranus, Neptune, and Jupiter. E) Dust provided the radioactive elements that initially heated the Sun. 68) 10

69) As the solar nebula contracts it A) reverses it direction of rotation. B) cools due to condensation. C) loses angular momentum. D) flattens out into the ecliptic plane around the Sun's poles. E) spins faster due to conservation of angular momentum. 69) 70) As a rotating gas cloud contracts, it spins A) faster due to an increase in angular momentum. B) faster due to conservation of angular momentum. C) slower due to conservation of angular momentum. D) slower due to a decrease in angular momentum. E) at a constant rate. 70) 11