Name: Period: Date: Astronomy Ch. 6 The Solar System 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) Ceres. C) Vesta. D) Gaspra. E) Eros. 1) 2) Which planet by itself contains the majority of mass of all the planets? A) Venus B) Jupiter C) Saturn D) Uranus E) the earth 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) constant since prehistoric times. E) slow and steady since the discovery of the telescope by Galileo. 3) 4) What is the goal of comparative planetology? A) to help plan future visits by unmanned probes, orbiters, and rovers B) to find which planets will be most suitable for future colonization C) to determine the origin and evolution of the solar system D) to use planetary positions to foretell the future E) to find out how our own solar system compares with extrasolar ones 4) 5) What is true about solar system densities? A) The asteroids all have about the same density. B) Saturn has the same density as water. C) Planetary density increases with increasing distance from the Sun. D) In differentiated bodies, the denser materials lie near their surfaces. E) The denser planets lie closer to the Sun. 5) 6) The planet's orbital period is: A) the time its magnetic field takes to spin once. B) the time it takes for a satellite to orbit it. C) the time it takes it to rotate and have the same face toward us again. D) the time it takes to return to the same location in the sky, relative to the Sun. E) the time it takes for it to retrograde back to the same position as we pass it. 6) 7) Masses of the planets are easiest to determine if: A) they are dense and easily deflect the path of passing spacecraft. B) they are terrestrial and the extra size of the planet's disk can be measured. C) they have natural satellites whose motions can be precisely measured. D) they are jovian and their oblateness can be found. E) they move rapidly and their periods are easily measured. 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) surface area B) diameter C) radius squared D) radius E) volume 8) 9) Which of these bodies has the lowest density? A) a comet B) an asteroid C) Saturn D) Kuiper Belt objects E) Jupiter 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) each one has a large satellite that interferes with this measurement. C) they are all gas giants. D) they rotate so fast. 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 known size and distance from Earth. B) a solid surface. C) rings. D) moons. E) planets further from the Sun than itself. 11) 12) The plane in which almost all planets orbit the sun is called the: A) node. B) equator of the solar system. C) ecliptic. D) galactic plane. E) equant. 12) 13) Which statement about the motion of the planets is incorrect? A) The orbits of most planets are almost circular, with low eccentricities. B) All revolutions of major planets are counterclockwise. C) Most planets rotate in the counterclockwise direction when viewed from the North. D) Most orbit above the Sun's equator. E) Most planets move in the Earth's equatorial plane. 13) 2
14) Mercury's most unusual orbital feature, as compared to the other planets, is A) its orbital period. B) the shape of its orbit. C) that it has no moons. D) the size of the planet. E) the size of its orbit. 14) 15) What aspects of the planets orbits are nearly the same for most planets? A) orbital period and distance from the Sun B) shape and tilt from the ecliptic C) shape and distance from the Sun D) tilt from the ecliptic and distance from the Sun E) orbital period and shape 15) 16) Planetary orbits A) have the Sun at their exact center. B) are almost circular, with low eccentricities. C) are spaced more closely together as they get further from the Sun. D) are evenly spaced throughout the solar system. 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) All terrestrials are more dense than any of the jovians. C) Made from the same solar nebula, they are all similar. D) The closer a planet lies to the Sun, the less its density. 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) Jupiter, Saturn, Uranus, Neptune, and Pluto B) everything past Mars and the asteroid belt C) only Jupiter and Saturn D) Jupiter, Saturn, Uranus, and Neptune only E) only Jupiter 18) 19) In composition and mass and density, Jupiter is most like: A) a gigantic asteroid. B) a large terrestrial planet. C) a huge comet. D) a huge Kuiper belt Object. E) the Sun. 19) 20) Which characteristic listed below describes the jovian planets? A) solid surfaces B) close to the Sun C) low density D) small masses E) slow rotational period 20) 3
21) Which of the characteristics below describes the terrestrial planets? A) having rings B) possessing weak magnetic fields C) large and gaseous D) widely spaced through the outer solar system E) small, dark and icy 21) 22) 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. 22) 23) Most asteroids are found: A) between the Earth and Sun. B) orbiting the jovian planets in captured, retrograde orbits. C) in the orbit of Jupiter, but 60 degrees ahead or behind it. D) beyond the orbit of Neptune. E) between the orbits of Mars and Jupiter. 23) 24) The Kuiper Belt is found where in the solar system? A) beyond the orbit of Neptune B) sixty degrees ahead or behind Jupiter C) among the orbits of the terrestrial planets D) between the orbits of Jupiter and Uranus E) between the orbits of Mars and Jupiter 24) 25) In composition and density, the asteroids most resemble: A) pieces of terrestrial planets. B) Kuiper Belt objects like Pluto. C) comets. D) jovian moons. E) the Sun. 25) 26) In composition, asteroids and meteoroids are most like A) comets. B) Kuiper Belt objects. C) jovian planets. D) terrestrial planets. E) the moons of Jupiter. 26) 27) The difference between a meteoroid and an asteroid is the object's A) size. B) location in the solar system. C) composition. D) shape. E) orbital period. 27) 4
28) The smallest sort of interplanetary matter is called A) a meteoroid. B) an asteroid. C) a Kuiper Belt Object. D) a comet. E) interplanetary dust. 28) 29) Which of the following is not icy in composition? A) Kuiper Belt Objects B) most Jovian satellites C) comet nuclei D) asteroids E) the polar cap of Mars 29) 30) The most detailed look we've had of an asteroid comes from A) Earth orbital X-ray images. B) ground based radar images. C) high-altitude UV spectroscopy. D) spacecraft sent to an asteroid. E) ground based optical images.. 30) 31) The Kuiper Belt is an "outer asteroid belt" consisting of what types of solar system bodies? A) meteoroids B) terrestrial planets C) icy cometlike bodies D) jovian planets E) asteroids 31) 32) Which of the following have an icy composition? A) meteoroids B) the surface of Mars C) most asteroids D) comets E) meteorites and most asteroids 32) 33) A meteorite is A) a chunk of space debris that has struck the ground. B) a streak of light in the atmosphere. C) an irregularly shaped body, mostly found orbiting between Mars and Jupiter. D) a chunk of space debris orbiting the Earth. E) an icy body with a long tail extending from it. 33) 34) Objects in the Kuiper belt A) are dense, like the iron meteorites. B) are in random orbits at all inclinations to the ecliptic. C) are the sources of long-period comets. D) lie beyond the orbit of Neptune and perpendicular to the ecliptic.. E) lie beyond the orbit of Neptune, and close to the ecliptic. 34) 5
35) Which of the following is considered "interplanetary matter"? A) Ganymede B) Comet Hale-Bopp C) Triton D) Titan E) the Moon 35) 36) The tail of a comet always points A) toward Earth and never varies. B) toward the Sun and disappears at perihelion. C) in the direction of the comet's motion. D) away from the Sun and becomes longest and brightest at perihelion. E) away from the Sun and disappears at perihelion. 36) 37) A gravitational "sling-shot": A) causes comets to crash into planets, such as Jupiter in 1994. B) explains how the solar system was formed after a near collision with another star. C) changes the speed and direction of a spacecraft nearing a massive planet. D) is the accepted theory for the formation of the asteroid belt. E) allowed the Apollo astronauts to reach the Moon in 1969. 37) 38) Which of these spacecraft went into orbit about Saturn in July 2004? A) New Horizons B) Galileo C) Voyager 2 D) NEAR-Shoemaker E) Cassini 38) 39) Which spacecraft gave us our best information about Mercury, until Messenger arrives in 2009? A) Pioneer 10 B) Viking 2 C) Voyager I D) Mariner 10 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) Venera 14 lander. B) Venera 15 orbiter. C) Messenger orbiter. D) Magellan. E) Global Surveyor. 40) 41) The only spacecraft to be intentionally crashed into Jupiter was: A) Voyager 1. B) Galileo. C) Magellan. D) Pioneer 11. E) Cassini. 41) 6
42) The "Grand Tour" of all four jovians was conducted by: A) Voyager 1 and 2 both. B) Pioneer 11. C) Voyager 2. D) Galileo. E) Cassini. 42) 43) Our best close-up views of the jovian moons came from the many passes by: A) Cassini. B) Galileo. C) Global Surveyor. D) Voyager 2. E) New Horizons. 43) 44) The Mariner 10 spacecraft visited which bodies in the solar system? A) Mars and Mercury B) the jovian planets C) Venus and Mars 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) Saturn's polar regions. B) Uranus. C) Titan. D) Jupiter. E) Pluto. 45) 46) Which objects in the solar system have been least modified since the formation of the solar system? A) terrestrial planets B) jovian moons C) asteroids D) meteoroids E) Kuiper Belt objects 46) 47) Which of these was the first to cross the asteroid belt and head to Jupiter? A) Galileo B) Pioneer 10 C) Voyager I D) Mariner 10 E) Cassini 47) 48) Which statement about Mercury is not correct? A) Mariner 10 needed a gravity assist from Venus to get to it in 1974. B) About half of its surface was mapped by Mariner 10. C) It is the target for planned orbiters from NASA, Japan, and the ESA. D) Mariner 10 is now dead, but still in orbit about Mercury. E) Mariner 10 revealed its cratered surface looking much like our Moon. 48) 7
49) Which of these landed on Venus? A) Venera 7 B) Viking 2 C) Rover Spirit D) Surveyor 7 E) NEAR-Shoemaker 49) 50) As the solar nebula contracts due to gravitation, the cloud A) spins faster. B) expands. C) changes direction of motion. D) begins to cool. E) becomes more spherical in shape. 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) between the orbits of Mars and Jupiter B) sixty degrees ahead or behind Jupiter C) beyond the orbit of Neptune D) between the orbits of Jupiter and Uranus E) among the orbits of the terrestrial planets 52) 53) What is the role of irregularities in the solar system in terms of theories of its origin? A) The solar system has no irregularities; it is perfectly regular and orderly. 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) Theories of the solar system are entirely based on the many irregularities found among the planets and moons. 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) Planets should rotate counterclockwise as well. B) All the planets should orbit the sun counterclockwise. C) The ecliptic is the equator for the Sun. D) Larger planets should form closer to their star, where there is more debris. E) All the planets should follow the ecliptic plane. 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) interstellar magnetism generated by pulsars D) the Big Bang E) the formation of our arm of the Milky Way 55) 8
56) The meteorites that strike Earth are A) mostly made of iron. B) pieces of comets that fall to Earth. C) material from outside our solar system. D) the oldest rocks known. E) the remains of the planet between Mars and Jupiter. 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) the existence of the asteroid belt between Jupiter and Neptune. D) that the inner planets have more hydrogen and helium in their atmospheres than do the outer planets. E) all observed properties of the solar system. 57) 58) Planetary orbits A) are evenly spaced throughout the solar system. B) have the Sun at their exact center. C) are almost circular, with low eccentricities. D) are highly inclined to the ecliptic. E) are spaced more closely together as they get further from the Sun. 58) 59) What is true about solar system densities? A) Saturn has the same density as water. B) In differentiated bodies, the denser materials lie near their surfaces. C) The asteroids all have about the same density. D) The denser planets lie closer to the Sun. E) Planetary density increases with increasing distance from the Sun. 59) 60) The jovian planets A) all lie less than 5 AU from the Sun. B) all have rings around their equators. C) have satellite systems with less than 4 moons. D) all spin slower than the earth. 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) fragmentation B) condensation C) core-accretion D) differentiation E) collision 61) 62) What happens when a solar nebula contracts? A) It heats up. B) It flattens out. C) It spins faster. 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) The Sun's gravity forced them into these orbits. B) This happened purely by chance. C) The angular momentum of the solar system was kept to a minimum this way. D) The early solar nebula flattened into a disk. E) Comets would have wiped out any not in this protected plane. 63) 64) What is the process of accretion? A) the process by which the solar nebula became heated during its collapse B) the separation of materials in a protoplanet by density, with dense material in core C) the period of time during which the Sun swept away all the excess material in the solar nebula D) growth of an object by the accumulation of matter E) the breakup of large objects by violent collisions with other similar-sized objects 64) 65) Conservation of angular momentum means that a spinning body tends to A) slow down. B) gravitationally collapse. C) keep spinning. D) wobble into an eccentric orbit. E) fly apart. 65) 66) Dust is an important part of the nebular theory of solar system formation because dust is needed to explain A) how the inner planets came to be rocky bodies. B) how the initial cloud heated as it contracted. C) how the outer planets came to be gaseous bodies. D) why the icy bodies are located so far from the Sun. E) how the initial cloud cooled enough to collapse. 66) 67) What factor caused different planets to form out of different types of material? A) The variation in temperature throughout the solar nebula; the higher the temperature, the lower the percentage of light elements in the forming planet. B) The quantity of dust particles in the solar nebula; more dust caused some planets to contain heavier elements. C) The angular momentum of the solar nebula pushed the heavy elements towards the outer regions of the nebula. D) The angular momentum of the forming planet; faster rotating planets lost the lightest elements. E) The innate variation of chemical composition of the original nebula; the outer parts of the nebula contained a greater abundance of heavy elements. 67) 68) What was the primary role of dust in the formation of the solar system? A) Dust provided the radioactive elements that initially heated the Sun. B) Dust acted as condensation nuclei; platforms to which other particles could attach and form larger particles of matter. 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 veiled the process by which our solar system formed. 68) 10
69) As the solar nebula contracts it A) flattens out into the ecliptic plane around the Sun's poles. B) loses angular momentum. C) reverses it direction of rotation. D) spins faster due to conservation of angular momentum. E) cools due to condensation. 69) 70) As a rotating gas cloud contracts, it spins A) at a constant rate. B) slower due to conservation of angular momentum. C) slower due to a decrease in angular momentum. D) faster due to an increase in angular momentum. E) faster due to conservation of angular momentum. 70) 11