Chapter 4: The Solar System: Interplanetary Matter and the Birth of the Planets

39) What is true about solar system densities? A) The denser planets lie closer to the Sun. B) In differentiated bodies, the denser materials lie near their surfaces. C) The asteroids all have about the same density. D) Saturn has the same density as water. E) Planetary density increases with increasing distance from the Sun.

A) The denser planets lie closer to the Sun.

59) A meteorite is A) a chunk of space debris that has struck the ground. B) a streak of light in the atmosphere. C) an icy body with a long tail extending from it. D) a chunk of space debris orbiting the Earth. E) an irregularly shaped body, mostly found orbiting between Mars and Jupiter

A) a chunk of space debris that has struck the ground.

42) The Kuiper Belt is found where in the solar system? A) beyond the orbit of Neptune B) among the orbits of the terrestrial planets C) between the orbits of Mars and Jupiter D) between the orbits of Jupiter and Uranus E) sixty degrees ahead or behind Jupiter

A) beyond the orbit of Neptune

67) If a cometʹs ion tail is pointing perpendicular to its direction of travel, the comet is A) close to or at perihelion. B) close to or at aphelion. C) moving closer to the Sun. D) moving away from the Sun. E) A cometʹs tail never points perpendicular to its motion.

A) close to or at perihelion.

34) Density is defined as A) mass per unit volume. B) weight per square inch. C) size divided by weight. D) mass times weight. E) weight divided by the planetʹs radius.

A) mass per unit volume.

51) The most detailed look weʹve had of an asteroid comes from A) spacecraft sent to an asteroid. B) ground based optical images. C) Earth orbital X-ray images. D) ground based radar images. E) high-altitude UV spectroscopy.

A) spacecraft sent to an asteroid.

55) Iron meteorites are believed to come from A) the core of a differentiated asteroid, now broken up. B) the crust of a differentiated asteroid, now broken up. C) a broken up cometary nucleus. D) debris from the Kuiper Belt. E) interstellar space.

A) the core of a differentiated asteroid, now broken up.

36) Which planet by itself contains the majority of mass of all the planets? A) Jupiter B) Saturn C) the Earth D) Venus E) Uranus Ans

A) Jupiter

58) A meteor is A) a chunk of space debris that has struck the ground. B) a streak of light in the atmosphere. C) an icy body with a long tail extending from it. D) a chunk of space debris orbiting the Earth. E) an irregularly shaped body, mostly found orbiting between Mars and Jupiter.

B) a streak of light in the atmosphere.

40) The jovian planets A) all lie less than 5 AU from the Sun. B) all have rings around their equators. C) all spin slower than the Earth. D) have satellite systems with less than 4 moons. E) are all much more dense than any of the terrestrial planets.

B) all have rings around their equators.

61) The orbits of most comets A) are like the planets, fairly circular and in the ecliptic plane. B) lie almost entirely beyond the orbit of Neptune. C) have perihelions within the orbits of Mercury. D) go no farther out than Pluto, then return to the sun again. E) are shorter than the 76-year period for Comet Halley.

B) lie almost entirely beyond the orbit of Neptune.

62) 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) are the sources of long-period comets. D) are dense, like the iron meteorites. E) lie beyond the orbit of Neptune and perpendicular to the ecliptic.

B) lie beyond the orbit of Neptune, and close to the ecliptic.

68) As the solar nebula contracts, it A) flattens out into the ecliptic plane around the Sunʹs poles. B) spins faster due to conservation of angular momentum. C) cools due to condensation. D) loses angular momentum. E) reverses its direction of rotation.

B) spins faster due to conservation of angular momentum.

53) In July 2011, the Dawn probe entered orbit around A) the asteroid Ceres. B) the asteroid Vesta. C) the comet Wild. D) the asteroid Ida. E) the asteroid Gaspra.

B) the asteroid Vesta.

54) Relative to the comet, the direction of the ion tail tells us A) where the ecliptic is. B) the direction of the Sun. C) the velocity of the comet. D) the direction the comet is traveling. E) where the comet came from.

B) the direction of the Sun.

69) In terms of composition A) all planets condensed from the same nebula, and have similar compositions. B) the jovian planets are more like the Sun than are the terrestrials. C) the terrestrials are more like the Sun, since they formed close to it. D) the Sun is unique, made of nothing but hydrogen and helium. E) the jovian planets are made only of ice, and the terrestrials only of rock.

B) the jovian planets are more like the Sun than are the terrestrials.

72) The larger terrestrial planets have surface features that tend to be A) older. B) younger. C) more cratered. D) more icy. E) more rocky.

B) younger.

65) The nucleus of a comet is typically A) a few meters in diameter. B) very durable, made of iron. C) a few kilometers in size, and very low in density. D) a few hundred kilometers across, and bright, shiny white from its ices. E) located between the orbits of Mars and Jupiter.

C) a few kilometers in size, and very low in density.

37) Planetary orbits A) are evenly spaced throughout the solar system. B) are highly inclined to the ecliptic. 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.

C) are almost circular, with low eccentricities.

63) Which of these bodies are most likely to break up over time? A) asteroids in the main belt B) jovian satellites C) comet nuclei D) Kuiper Belt bodies E) Trojan asteroids

C) comet nuclei

46) Which of the following have an icy composition? A) most asteroids B) meteoroids C) comets D) the surface of Mars E) meteorites and most asteroids

C) comets

78) Exoplanets known as super-Earths A) have masses comparable to that of Jupiter. B) have masses comparable to that of Neptune. C) have masses 2-10 times that of Earth. D) orbit extremely massive stars. E) have yet to be observed.

C) have masses 2-10 times that of Earth.

48) The most distant objects in our solar system are A) in the Kuiper Belt. B) the jovians. C) in the Oort Cloud. D) short period comets. E) the Trojan asteroids.

C) in the Oort Cloud.

74) Most of the extrasolar planets found so far were detected by A) noting the drop in the starʹs light as the planet transits its disk. B) imaging them with the HST in the infrared, where they are easier to stop. C) noting the Doppler shifts of the star as the planet orbits it from side to side. D) receiving radio transmissions from them, much like Jupiter emits. E) detecting the oxygen in their atmospheres spectroscopically.

C) noting the Doppler shifts of the star as the planet orbits it from side to side.

45) Which of the following does not fall into the category of interplanetary debris? A) comets B) meteoroids C) rings around the jovian planets. D) Trojan asteroids E) Kuiper Belt bodies

C) rings around the jovian planets.

47) The Trojan asteroids are found A) orbiting around the Kuiper Belt body Hector. B) with the others, between Mars and Jupiter; their red color gives them their name. C) sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun. D) beyond Neptune, with orbits similar to Plutoʹs. E) closer on average to the Sun than is the Earth.

C) sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun.

60) Long-period comets are believed to originally come from A) the asteroid belt. B) the Kuiper belt. C) the Oort cloud. D) the satellite system of Jupiter. E) the interstellar medium.

C) the Oort cloud.

57) Meteorites are important because A) they contain pristine material from the solar nebula. B) large ones may cause mass extinctions. C) some come from the Moon and Mars, as well as the asteroid belt. D) All of the above are true. E) None of the above are true.

D) All of the above are true.

41) The largest asteroid, and probably the only one to be a spherical ʺworldʺ is A) Eros. B) Ida. C) Vesta. D) Ceres. E) Gaspra.

D) Ceres.

35) Which of the following are the jovian planets? A) Jupiter, Saturn, Uranus, Neptune, and Pluto B) only Jupiter C) only Jupiter and Saturn D) Jupiter, Saturn, Uranus, and Neptune only E) everything past Mars and the asteroid belt

D) Jupiter, Saturn, Uranus, and Neptune only

49) The first spacecraft to land on the surface of an asteroid was named A) Stardust. B) Giotto. C) Galileo. D) NEAR. E) Dawn.

D) NEAR.

64) The Manicouagan reservoir near Quebec is an example of A) a volcanic event. B) cometary debris. C) Earthʹs interaction with a cometʹs dust tail. D) a large meteorite impact. E) a micrometeorite impact.

D) a large meteorite impact.

44) The Oort Cloud is believed to be A) a flattened belt of cometary nuclei just beyond the orbit of Neptune. B) the circular disk of gas around the Sunʹs equator from which the planets formed. C) a grouping of asteroids and meteoroids between the orbits of Mars and Jupiter. D) a spherical cloud of cometary nuclei far beyond the Kuiper Belt. E) the great nebula found just below the belt stars of Orion.

D) a spherical cloud of cometary nuclei far beyond the Kuiper Belt.

38) Which of the following is not icy in composition? A) comet nuclei B) Kuiper Belt Objects C) the polar cap of Mars D) asteroids E) most jovian satellites

D) asteroids

43) The tail of a comet always points A) toward the Sun and disappears at perihelion. B) toward Earth and never varies. C) away from the Sun and disappears at perihelion. D) away from the Sun and becomes longest and brightest at perihelion. E) in the direction of the cometʹs motion.

D) away from the Sun and becomes longest and brightest at perihelion.

1) As a rotating gas cloud contracts, it spins A) faster due to an increase in angular momentum. B) slower due to a decrease in angular momentum. C) at a constant rate. D) faster due to conservation of angular momentum. E) slower due to conservation of angular momentum.

D) faster due to conservation of angular momentum.

66) Before it arrived in orbit about Jupiter, the Galileo spacecraft flew past A) Comet Halley. B) Mars. C) Saturn. D) the asteroid Gaspra. E) the asteroid Ceres.

D) the asteroid Gaspra.

52) Before it arrived in orbit about Eros, the NEAR spacecraft visited A) Venus. B) the Moon. C) Mars. D) the asteroid Mathilde. E) the asteroid Gaspra.

D) the asteroid Mathilde.

56) Meteor showers are A) usually annual events, as the orbits again intersect. B) caused by the Earth passing near the orbit of an Earthgrazing asteroid. C) caused by the Earth passing near the orbit of an old short-period comet. D) Both A and B are correct. E) Both A and C are correct.

E) Both A and C are correct.

75) Which statement about extrasolar planets found to date is true? A) All are terrestrials, comparable in size to Earth. B) Few are found by Doppler shifts of their stars, due to their gravity. C) All lie more than 2 AU from their star. D) Most have orbital periods of more than a year. E) Some are so close to their stars that their periods are just a few days.

E) Some are so close to their stars that their periods are just a few days.

12) Due to their great masses, all four jovian worlds are much denser than the Earth.

False

16) Meteor showers are the result of collisions between asteroids.

False

2) Plutoʹs orbit has a lower inclination to the ecliptic than any planet.

False

20) Comets are not actually members of the solar system, but have been captured by the Sun.

False

21) The Oort Cloud lies closer to the Sun than the Kuiper Belt.

False

28) Astronomers have not yet been able to detect planets outside our solar system.

False

3) One characteristic of the terrestrial planets is their extensive moon systems.

False

33) The fact that we donʹt see very many Earthlike planets in orbit around other stars is an indication that Earthlike planets are rare.

False

4) All the planetʹs orbits are evenly spaced.

False

5) Earth is nearly twice as large as Venus.

False

6) All the planets revolve around the Sun in the same direction, except for Venus and Uranus.

False

7) All the planets orbit the Sun in exactly the same plane as the Earth.

False

8) The two smallest planets, Mercury and Pluto, have no moons.

False

1) All the terrestrial planets lie inside the asteroid belt.

True

10) All jovian planets have rings around their equators and at least eight moons.

True

11) Pluto is more similar to the jovian planetʹs icy moons than to any of the other planets.

True

13) A Kuiper Belt object was discovered that may be larger than Pluto.

True

14) Barringer Crater in Arizona is an example of a meteorite impact.

True

15) Most astronomers now believe the demise of the dinosaurs 65 million years ago was caused by a large asteroid impacting the Yucatan peninsula area.

True

17) Carbonaceous asteroids contain fragile organic molecules.

True

18) Many astronomers now regard Pluto as just one of the largest of the thousands of Kuiper Belt bodies found beyond Neptune.

True

19) Cometary dust tails lag behind the bluish ion tails as the comet rounds the Sun. Answer: TRUE

True

22) Researchers estimate that there is more total mass in the Kuiper Belt than in the asteroid belt.

True

23) Some meteorites are believed to have come from Mars and the Moon.

True

24) As a rotating gas cloud contracts, it spins faster.

True

25) In the solar nebular theory, the dusty disk condensing around the Sunʹs equator became the ecliptic plane in which the planets then formed.

True

26) In addition to revolving around the Sun counter clockwise, most planets also rotate on their axis counter clockwise.

True

27) Any successful model for the formation of the solar system must explain why the orbits of the planets have low eccentricities.

True

29) We would expect other planets beyond our own solar system to orbit the equators of their home stars, as our own planets orbit the Sun.

True

30) In some cases, we have seen extrasolar planets pass in front of their stars.

True

9) All four jovian planets are thought to have cores larger than Earth.

True