Study Guide #3

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Where are most of the known asteroids found?
A) between the orbits of Mars and Jupiter
B) in the Kuiper belt
C) in the Oort cloud
D) between the orbits of the jovian planets
E) between the orbits of the terrestrial planets

2) Why did the solar nebula heat up as it collapsed?
A) Nuclear fusion occurring in the core of the protosun produced energy that heated the nebula.
B) As the cloud shrank, its gravitational potential energy was converted to kinetic energy and then into thermal energy.
C) Radiation from other nearby stars that had formed earlier heated the nebula.
D) The shock wave from a nearby supernova heated the gas.
E) Collisions among planetesimals generated friction and heat.

3) According to our theory of solar system formation, why do all the planets orbit the Sun in the same direction and in nearly the same plane?
A) The original solar nebula happened to be diskminusshaped by chance.
B) Any planets that once orbited in the opposite direction or a different plane were ejected from the solar system.
C) The laws of conservation of energy and conservation of angular momentum ensure that any rotating, collapsing cloud will end up as a spinning disk.
D) The Sun formed first, and as it grew in size it spread into a disk, rather like the way a ball of dough can be flattened into a pizza by spinning it.
E) Luck explains it, as we would expect that most other solar systems would not have all their planets orbiting in such a pattern.

4) The more massive planets in the solar system tend to be less dense than the lower mass planets.
A) True
B) False

5) As viewed from above the Earth's North Pole, all of the planets orbit the Sun in the same (counterclockwise) direction.
A) True
B) False

6) Rank the five terrestrial worlds in order of size from smallest to largest:
A) Mercury, Venus, Earth, Moon, Mars
B) Mercury, Moon, Venus, Earth, Mars
C) Moon, Mercury, Venus, Earth, Mars
D) Moon, Mercury, Mars, Venus, Earth
E) Mercury, Moon, Mars, Earth, Venus

7) The core, mantle, and crust of a planet are defined by differences in their
A) viscosity.
B) temperature.
C) strength.
D) composition.
E) geological activity.

8) The terrestrial planet cores contain mostly metal because
A) the entire planets are made mostly of metal.
B) metals condensed first in the solar nebula and the rocks then accreted around them.
C) metals sank to the center during a time when the interiors were molten throughout.
D) radioactivity created metals in the core from the decay of uranium. E) convection carried the metals to the core.

9) Which of the following best describes convection?
A) It is the process by which rocks sink in water.
B) It is the process in which warm material expands and rises while cool material contracts and falls.
C) It is the process in which warm material gets even warmer and cool material gets even cooler.
D) It is the process in which a liquid separates according to density, such as oil and water separating in a jar.
E) It is the process in which bubbles of gas move upward through a liquid.

10) The three principal sources of the internal heat of terrestrial planets are
A) conduction, differentiation, and accretion.
B) accretion, differentiation, and radioactivity.
C) accretion, differentiation, and eruption.
D) convection, differentiation, and eruption.
E) conduction, convection, and eruption.

11) The three principal sources of the internal heat of terrestrial planets are
A) conduction, differentiation, and accretion.
B) accretion, differentiation, and radioactivity.
C) accretion, differentiation, and eruption.
D) convection, differentiation, and eruption.
E) conduction, convection, and eruption.

12) What are the conditions necessary for a terrestrial planet to have a strong magnetic field?
A) a molten metallic core only
B) fast rotation only
C) a rocky mantle only
D) both a molten metallic core and reasonably fast rotation
E) both a metal core and a rocky mantle

13) Which of the following does not have a major effect in shaping planetary surfaces?
A) impact cratering
B) volcanism
C) tectonics
D) erosion
E) magnetism

14) Which of the following describes volcanism?
A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface
B) the eruption of molten rock from a planet's interior to its surface
C) the disruption of a planet's surface by internal stresses
D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather

15) A planet is most likely to have tectonic activity if it has
A) low surface gravity.
B) high surface gravity.
C) low internal temperature.
D) high internal temperature.
E) a dense atmosphere.

16) How have we been able to construct detailed maps of surface features on Venus?
A) by studying Venus from Earth with powerful telescopes
B) by studying Venus with powerful telescopes on spacecraft that were sent to orbit Venus
C) by making computer models of geological processes on Venus
D) by using radar from spacecraft that were sent to orbit Venus
E) by landing spacecraft on the surface for close-up study

17) Which of the following show evidence of ancient river beds?
A) the Moon
B) Mercury
C) Venus
D) Mars
E) all of the above

18) There is no erosion of surface features on the Moon.
A) True
B) False

19) Which of the following planets has the least substantial atmosphere? A) Venus
B) Earth
C) Mars
D) Neptune
E) Mercury

20) Why does Venus have such a great difference in temperature between its "no atmosphere" temperature and its actual temperature?
A) It has a slow rotation.
B) It is so close to the Sun.
C) It has a large amount of greenhouse gases in its atmosphere.
D) It has a high level of volcanic activity.
E) It has no cooling effects from oceans.

21) Which of the following gases absorbs ultraviolet light best?
A) carbon dioxide
B) nitrogen
C) oxygen
D) hydrogen
E) ozone

22) What is the troposphere?
A) the lowest layer in the atmosphere
B) the part of the atmosphere that absorbs optical light
C) the part of the atmosphere that absorbs ultraviolet
D) the part of the atmosphere that absorbs X-rays
E) the highest layer in the atmosphere

23) Where is most of the water on Mars?
A) in its clouds
B) in its polar caps and subsurface ground ice
C) frozen on the peaks of its tall volcanoes
D) in deep underground deposits
E) distributed evenly throughout its atmosphere

24) Why is Mars red?
A) It is made primarily of red clay.
B) Its surface rocks were rusted by oxygen.
C) Its atmosphere scatters blue light more effectively than red light. D) Its surface is made of ices that absorb blue light.
E) Its surface is made of ices that absorb red light.

25) Without greenhouse gases, Earth's surface would be frozen over.
A) True
B) False

26) How much energy does Jupiter emit compared with how much it receives from the Sun?
A) It emits 10 times as much.
B) It emits twice as much.
C) It emits half as much.
D) It emits 10 percent as much.
E) It emits 1 percent as much.

27) Why is Neptune denser than Saturn?
A) It has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks.
B) It has a greater proportion of hydrogen than Saturn.
C) The extra mass of Neptune compresses its interior to a greater extent than that of Saturn.
D) Its hydrogen is molecular, whereas Saturn's hydrogen is atomic.
E) It is not denser than Saturn.

28) What is Jupiter's Great Red Spot?
A) the place where reddish particles from Io impact Jupiter's surface
B) a hurricane that comes and goes on Jupiter
C) a large mountain peak poking up above the clouds
D) a long-lived, high-pressure storm
E) the place where Jupiter's aurora is most visible

29) Why are there no impact craters on the surface of Io?
A) It is too small to have been bombarded by planetesimals in the early solar system.
B) Jupiter's strong gravity attracted the planetesimals more strongly than Io and thus none landed on its surface.
C) Io did have impact craters but they have all been buried in lava flows.
D) Any craters that existed have been eroded through the strong winds on Io's surface.
E) Io's thick atmosphere obscures the view of the craters.

30) How many jovian moons are larger than the planet Pluto?
A) 1, only Ganymede
B) 2, Callisto and Ganymede
C) 4, all the Galilean moons
D) 6, all the Galilean moons plus Titan and Triton
E) none (no moons are larger than any planet)

31) What is the most abundant gas in Titan's atmosphere? A) methane
B) nitrogen
C) hydrogen compounds
D) oxygen
E) argon

32) Why do astronomers believe Triton may have been a planet that was captured by Neptune? A) It orbits Neptune in the opposite direction of Neptune's rotation.
B) It is too large to have been formed in the jovian nebula that formed Neptune.
C) It has an atmosphere and a measurable greenhouse effect.
D) It undergoes seasonal changes.
E) It is colder than any other moon or planet.

33) What is a Roche zone?
A) a bright layer of gas on Jupiter
B) the region near a planet where tidal forces would tear apart an object held together only by gravity
C) the region within a planet's magnetic field where charged particles accumulate
D) the region surrounding a planet where it may have large moons
E) a region where gravitational resonances clear a gap in a planet's rings

34) Hydrogen exists as a gas, liquid, and solid within Jupiter.
A) True
B) False

35) Jupiter does not have seasons because it has no appreciable axis tilt.
A) True
B) False

36) What is the hydrosphere?
A) another name for the Earth's oceans
B) the layer of the Earth's atmosphere that contains the most water vapor
C) another name for the Earth, since it contains so much water
D) a layer of water between the mantle and the crust
E) a name for the liquid and frozen water on Earth's surface

37) How fast do plates move on the Earth?
A) a few centimeters per year
B) a few millimeters per century
C) a few kilometers per century
D) quite fast, but only during earthquakes
E) about 1 mile per hour

38) Ridges in the middle of the ocean are places where
A) one plate slides under another, returning older crust to the mantle.
B) hot mantle material rises upwardand spreads sideways, pushing the plates apart.
C) plates push together, creating ocean mountain chains.
D) plates slip sideways relativfe to one another.

39) Why does the burning of fossil fuels increase the greenhouse effect on Earth?
A) Burning fuel warms the planet.
B) Burning releases carbon dioxide into the atmosphere.
C) Burning depletes the amount of ozone, thereby warming the planet.
D) Burning produces infrared light, which is then trapped by existing greenhouse gases.
E) All of the above are true.

40) From where did the molecular oxygen in the Earth's atmosphere originate? A) photosynthesis from plant life
B) photosynthesis from single-celled organisms
C) outgassing from volcanos
D) atmospheric bombardment
E) oxidation of surface rocks

41) Earth outgassed as much carbon dioxide as Venus, but it is locked up in the oceans and rocks.
A) True
B) False