Question 1
. The average age of the surface of Venus has been determined primarily from
Answer
.
. 1. soil analysis by Russian landers.
.
.
. 2. the number of impact craters per unit area of surface.
.
.
. 3. radio-isotope analysis of rocks brought back from Venus by space probes.
.
.
. 4. the amount of weathering of lava flows imaged by the Magellan radar mapper.
.
. 2 points
Question 2
. The geology and geography of the surface of Venus is best described as Answer
.
. 1. heavily cratered, with no major volcanoes or lava flows.
.
.
. 2. colliding surface plates with long mountain chains, rift valleys, and deep subduction
. trenches.
.
.
.
. 3. mostly volcanic plains, with two continent-sized uplands and a number of large
. volcanoes.
.
.
.
. 4. volcanoes and volcanic uplifts in the northern hemisphere and cratered plains in the
. southern
.
hemisphere.
. 2 points
Question 3
. Several components of the atmosphere and the environment on Mars render it sterile
and antiseptic and would destroy life on the planet. Which of the following is NOT
one of these factors? Answer
.
. 1. solar UV radiation, which is not absorbed by the thin atmosphere
.
.
. 2. sulfuric acid droplets in the atmosphere
.
.
. 3. ozone in the atmosphere produced by solar UV light
.
.
. 4. hydrogen peroxide in the soil
.
. 2 points
Question 4
. Mercury appears from spacecraft photographs to resemble the Moon in its surface
features but with one important difference: Answer
.
. 1. the presence of retrograde direction of spin compared to most other planets and moons.
.
.
. 2. the presence of clouds and a measurable and significant atmosphere on Mercury.
.
.
. 3. the presence of extensive plains between craters, in contrast to the surface of the Moon.
.
.
. 4. evidence of active volcanoes on Mercury.
.
. 2 points
Question 5
. The internal structure of Mercury is a Answer
.
. 1. dense iron core taking up almost half of the volume of the planet and a rocky mantle
. surrounding
.
the core.
.
.
. 2. thick rocky mantle taking up most of the volume of the planet, overlaying a small but
. dense
. iron core.
.
.
. 3. rocky core surrounded by liquid metallic hydrogen and a hydrogen-helium atmosphere.
.
.
. 4. rocky core with a liquid (or perhaps frozen) water mantle and icy surface.
.
. 2 points
Question 6
. One chemical element that plays a major role in the coloring and chemistry of the
Venusian atmosphere and clouds, and is suspected of coming from volcanic
eruptions, is Answer
.
. 1. sulfur (as dust), sulfur dioxide, and sulfuric acid droplets.
.
.
. 2. chlorine (as gas), hydrogen chloride, and hydrochloric acid droplets.
.
.
. 3. iron (as red dust), iron oxides, and iron sulfides.
.
.
. 4. nitrogen (as gas), nitric oxide, and nitric acid droplets.
.
. 2 points
Question 7
. Which planet is the hottest one in the solar system, measured at the surface?
Answer
.
. 1. Mercury
.
.
. 2. Venus
.
.
. 3. Mars
.
.
. 4. Earth
.
. 2 points
Question 8
. How does Mercury rotate, relative to the Sun? Answer
.
. 1. Mercury rotates in a retrograde direction; consequently, the Sun rises in the west each
. day. and sets in the east.
.
.
. 2. Mercury rotates relatively quickly, so that a solar day (from sunrise to the next sunrise)
. on .Mercury is just a bit shorter than on the Earth.
.
.
. 3. Mercury alternately turns one side (Caloris Basin) toward the Sun at one perihelion and
. the. opposite side toward the Sun at the next perihelion.
.
.
. 4. Mercury turns the same side (Caloris Basin) toward the Sun at all times, much as the
. Moon
. turns the same side toward the Earth.
. 2 points
Question 9
. On which object would you find the great valley system Valles Marineris? Answer
.
. 1. Callisto (one of the large satellites of Jupiter)
.
.
. 2. Moon
.
.
. 3. Venus
.
.
. 4. Mars
.
. 2 points
Question 10
. The best images of the overall topology of Venus have been produced by Answer
.
. 1. reflection of microwave and short radio wave radiation from the surface by an orbiting
. spacecraft.
.
.
.
. 2. visible wavelength images from cameras on board an orbiting spacecraft.
.
.
. 3. photography from the Hubble Space Telescope at UV wavelengths to which the Venus
. atmosphere
.
and clouds are transparent.
.
.
. 4. imaging cameras on board two spacecraft that soft-landed on the surface of Venus.
.
. 2 points
Question 11
. How much mass will the Sun lose to space during its lifetime, through the solar
wind? Answer
.
. 1. a few thousandths of its total mass
.
.
. 2. well over one-half of its total mass
.
.
. 3. only a few millionths of its total mass
.
.
. 4. up to 25% of its total mass
.
. 2 points
Question 12
. Which of the following events is NOT a consequence of a coronal mass ejection
event from the Sun that is aimed toward Earth? Answer
.
. 1. damage to and even destruction of satellite electronics and power systems
.
.
. 2. disruption to radio transmission and electrical power systems on Earth
.
.
. 3. major health hazard for astronauts in orbit around Earth, particularly on the Moon
.
.
. 4. major hurricane
.
. 2 points
Question 13
. From which fusion reaction does the Sun derive its power? Answer
.
. 1. 4H ⇒ He
.
.
. 2.
4He
.
. 3.
2H
.
. 4.
3He
.
⇒O
⇒ He
.
.
⇒C
. 2 points
Question 14
. What process provides the power to maintain the Sun's radiative output? Answer
.
. 1. fusion of helium into carbon
.
.
. 2. decay of heavy elements in the solar core and the emission of neutrinos
.
.
. 3. fission of uranium to form lead
.
.
. 4. fusion of hydrogen into helium
.
. 2 points
Question 15
. Where is most of the mass of the Sun concentrated? Answer
.
. 1. in the photosphere
.
.
. 2. in the convective zone
.
.
. 3. in the inner core
.
.
. 4. spread uniformly throughout the Sun
.
. 2 points
Question 16
. The surprising fact about the magnetic field of Uranus compared with the magnetic
field of the Earth or Jupiter is that Answer
.
. 1. its axis is precisely aligned with the spin axis of the planet.
.
.
. 2. it is much more intense than that of any other planet.
.
.
. 3. its axis makes a larger angle to the planet's spin axis than that of any other planet.
.
.
. 4. it is extremely small and localized in specific regions of the planet.
.
. 2 points
Question 17
. The Great Dark Spot on Neptune Answer
.
. 1. has been visible through telescopes since at least as far back as 1665.
.
.
. 2. was the short-lived result of a comet crash in 1995.
.
.
. 3. disappeared sometime between the Voyager flyby in 1989 and when the Hubble
. Space
.
Telescope photographed Neptune in 1994.
.
.
. 4. came into existence sometime between the Voyager flyby in 1989 and when the
. Hubble
.
Space Telescope photographed Neptune in 1994.
.
. 2 points
Question 18
. Which planet has wide, bright rings that are easily visible from the Earth? Answer
.
. 1. Jupiter
.
.
. 2. Saturn
.
.
. 3. Venus
.
.
. 4. Neptune
.
. 2 points
Question 19
. Saturn is less massive than Jupiter but almost the same size. Explain. Answer
.
. 1. Saturn is rotating faster than Jupiter, and the increased centrifugal force results in a
. larger
. size.
.
.
. 2. Saturn's interior is hotter than that of Jupiter.
.
.
. 3. The smaller mass exerts less gravitational force and is unable to compress the mass
. as .much as in Jupiter.
.
.
. 4. Saturn is composed of lighter material than Jupiter.
.
. 2 points
Question 20
. Triton, the largest satellite of Neptune, has a Answer
.
. 1. densely cratered surface of ice with at least one very large ringed structure, indicating
. an .ancient asteroid impact.
.
.
. 2. surface of ice in which ancient, densely cratered regions are surrounded by
. interconnecting
.
systems of parallel ridges.
.
.
. 3. thick atmosphere that hides the surface from view.
.
.
. 4. surface of ice with frozen lakes, plumes of escaping gas, and few craters.
.
. 2 points
Question 21
. Where in the universe would you look for Ganymede? Answer
.
. 1. in the asteroid belt
.
.
. 2. near Jupiter because it is one of Jupiter's moons.
.
.
. 3. on the Moon because it is one of the largest maria
.
.
. 4. around the planet Mars because it is one of the moons of Mars
.
. 2 points
Question 22
. One of the characteristics of the magnetic field of Uranus is that its axis Answer
.
. 1. is tilted almost 60° to the axis of planetary rotation and is offset from the planet's
. center.
.
.
.
. 2. passes through the center of Uranus but is tilted almost 60° from the axis of rotation.
.
.
. 3. is aligned almost parallel to the planet's axis of rotation but is offset from the planet's
. center.
.
.
.
. 4. is aligned almost exactly along the planet's axis of rotation, through the center of Uranus.
.
. 2 points
Question 23
. Which gas is thought to be responsible for the tremendous eruptions of material from
Jupiter's innermost Galilean moon, Io, by providing the propulsive forces?
Answer
.
. 1. steam, or heated water vapor
.
.
. 2. sulfur dioxide, SO2
.
.
. 3. carbon dioxide, CO2
.
.
. 4. sulfur in vapor form
.
. 2 points
Question 24
. The rotation axis of which planet is tilted at 98° from the vertical to its
orbit?
Answer
.
. 1. Venus
.
.
. 2. Uranus
.
.
. 3. Earth
.
.
. 4. Neptune
.
. 2 points
Question 25
. Which planetary satellites are known to have plumes of gas escaping through their
surfaces? Answer
.
. 1. Io and Titan
.
.
. 2. Our Moon, Europa, and Miranda
.
.
. 3. Ganymede and Charon
.
.
. 4. Io and Triton
.
. 2 points
Question 26
. Which of the following processes has played the greatest role in shaping the surface
of the Moon? Answer
.
.
.
.
. 1. motions of tectonic plates, producing mountain ranges wherever they collide
.
. 2. impacts of interplanetary bodies of all sizes
.
. 3. erosion by wind and atmospheric gases
.
. 4. recent volcanic activity, producing large numbers of craterlike volcanic calderas
.
. 2 points
Question 27
. Air pressure falls by roughly a fraction of its pressure for every 5.5-km increase in
altitude. What, then, is the air pressure at the top of the troposphere, 11 km above
Earth's surface?
Answer
.
. 1. 50% of that at Earth's surface
.
.
. 2. zero
.
.
. 3. 25% of that at Earth's surface
.
.
. 4. 33% of that at Earth's surface
.
. 2 points
Question 28
. Earth's magnetosphere is the Answer
.
. 1. molten core of Earth, whose motions produce the magnetic field.
.
.
. 2. region beyond Earth's atmosphere where Earth's magnetic field protects us from
. the. solar wind.
.
.
. 3. region in Earth's crust near each magnetic pole.
.
.
. 4. atmospheric layer between the stratosphere and thermosphere where motions are
. governed
.
by Earth's magnetic field.
. 2 points
Question 29
. What is the most likely cause of the smooth and relatively crater-free surfaces of
lunar maria? Answer
.
. 1. The lava in these basins flowed in the relatively late geological history of the Moon,
. after
. the period of major bombardment.
.
.
. 2. Smoother sediments were left behind after water had flowed into the basins and
. evaporated
.
away.
.
.
. 3. Dust storms had eroded and smoothed the surface earlier in the Moon's history.
.
.
. 4. Volcanic ash rained on the surfaces of the basins in recent geological times, covering
. previous
.
craters.
. 2 points
Question 30
. What happened to the first major atmosphere to develop on the early Earth, which
consisted of hydrogen and helium? Answer
.
. 1. The molecules reacted chemically with Earth's hot surface and were absorbed into
.
.
.
.
.
. 2.
.
.
. 3.
.
.
.
. 4.
.
the. newly formed rocks.
The atmosphere drifted off into space as Earth's gravity was too weak to hold the
light
. molecules of hydrogen and helium.
The molecules combined chemically with one another to become molecules that
were
. heavy enough for Earth's gravity to pull into the surface rocks, where they are
now found.
The molecules were quickly absorbed into the ocean since they have high solubility
in .water.
. 2 points
Question 31
. Major maria on the Moon exist Answer
.
. 1. uniformly over the surface.
.
.
. 2. only on the Earth-facing side.
.
.
. 3. only in a band close to the equator.
.
.
. 4. only in the northern hemisphere.
.
. 2 points
Question 32
. What is the most probable heat source that produced extensive, maybe even total,
melting of the Moon at an early stage in its history? Answer
.
. 1. decay of radioactive elements within it and the impact energy of meteoritic
. bombardment
.
.
.
. 2. intense sunlight from the early and very active Sun
.
.
. 3. tidal flexing and distortion caused by its motion around Earth
.
.
. 4. nuclear fusion reactions occurring in its core
.
. 2 points
Question 33
. On Earth, the majority of earthquakes occur Answer
.
. 1. in the centers of tectonic plates (e.g., North American continent).
.
.
. 2. along regions of greatest thermal stress in arctic and antarctic regions.
.
.
. 3. along the boundaries of major tectonic plates.
.
.
. 4. along the zone of maximum tidal stress around the equator.
.
. 2 points
Question 34
. One of the major differences between Earth and its neighboring planets Venus and
Mars is the lack of large quantities of carbon dioxide in its atmosphere near the
surface of the planet. If all these planets were originally formed with significant
.
.
.
.
.
.
.
.
quantities of this gas in their atmospheres, where is this carbon dioxide on Earth
at the present time? Answer
1. dissolved in seawater, a situation that cannot arise on Venus or Mars
.
2. concentrated high in the atmosphere, where it contributes to the greenhouse effect
.
3. dissociated by solar UV light into carbon and oxygen, which now exist in abundance
. as .separate chemicals
.
4. locked up in rocks such as limestone, formed by life forms in the sea and on Earth's
. surface
.
. 2 points
Question 35
. Who first postulated that continents drift around over Earth's surface? Answer
.
. 1. James Van Allen
.
.
. 2. J. Tuzo Wilson
.
.
. 3. Alfred Wegener
.
.
. 4. Charles Darwin
.
. 2 points
Question 36
. The asteroid belt exists between the orbits of which planets? Answer
.
. 1. Jupiter and Saturn
.
.
. 2. Earth and Mars
.
.
. 3. Mars and Jupiter
.
.
. 4. Venus and Earth
.
. 2 points
Question 37
. Which planet is the largest in our solar system? Answer
.
. 1. Earth
.
.
. 2. Saturn
.
.
. .
.
. 3. Jupiter
.
.
. 4. Uranus
.
. 2 points
Question 38
. Most extrasolar planets have been found Answer
.
. 1. in globular clusters.
.
.
. 2. near the center of our Galaxy.
.
.
.
. 3. outside our Galaxy.
.
. 4. around stars in the disk of our Galaxy.
.
. 2 points
Question 39
. The average density of the large, outer planets is Answer
.
. 1. very much less than the density of water because of the amount of hydrogen
. they
. contain.
.
.
. 2. much higher than the density of Earth rocks, due to the great gravitational
. compression
.
of their interiors.
.
.
. 3. close to the density of basaltic rocks on Earth.
.
.
. 4. close to the density of water.
.
. 2 points
Question 40
. What is thought to be the physical mechanism that was responsible for the present
mix of chemical elements in the universe? Answer
.
. 1. Hydrogen and helium were formed in the Big Bang, whereas the heavier elements
. were
. made in the centers of stars.
.
.
. 2. All the known elements have been formed by the breakup (radioactivity) of the
. heavy
. elements formed in the initial Big Bang.
.
.
. 3. All the known elements were formed in the Big Bang.
.
.
. 4. Hydrogen and helium were formed in the Big Bang, whereas the heavier elements
. have
. been slowly forming by collisions in cold interstellar gas clouds.
. 2 points
Question 41
. A chunk of rock and metal 10 km in diameter orbiting the Sun would be called a(n)
Answer
.
. 1. asteroid.
.
.
. 2. meteoroid.
.
.
.
. 3. moon.
. .
. 4. comet.
.
. 2 points
Question 42
. Of the following objects in the solar system, which one has the greatest orbital
eccentricity and therefore the most elliptical orbit? Answer
.
. 1. Earth
.
.
. 2. Pluto
.
.
.
. 3. Mars
.
. 4. Mercury
.
. 2 points
Question 43
. The orbits of comets are Answer
.
. 1. primarily in the plane of the ecliptic and can extend far out beyond the orbit of Pluto.
.
.
. 2. primarily in the plane of the ecliptic and confined to distances closer to the Sun than
. approximately
.
the orbit of Pluto.
.
.
. 3. randomly oriented in the solar system and confined to distances closer to the Sun than
. approximately
.
the orbit of Pluto.
.
.
. 4. randomly oriented in the solar system and can extend far beyond the orbit of Pluto.
.
. 2 points
Question 44
. The asteroid belt exists between the orbits of the planets Answer
.
. 1. Jupiter and Saturn.
.
.
. 2. Earth and Mars.
.
.
. 3. Venus and Earth.
.
.
. 4. Mars and Jupiter.
.
. 2 points
Question 45
. Which spacecraft is the only one known to have landed on the surface of an
asteroid? Answer
.
. 1. Cassini
.
.
. 2. The Soviet Venera 8 spacecraft
.
.
. 3. Viking
.
.
. 4. NEAR Shoemaker
.
. 2 points
Question 46
. What is the typical distance between asteroids in the asteroid belt? Answer
.
. 1. 10 million km
.
.
. 2. 1.2 AU
.
.
. 3. 25 km
.
.
. 4. 6000 km
.
. 2 points
Question 47
. The estimated impact energy of the object that produced the Barringer Crater in
Arizona, in terms of explosive power (tons of TNT equivalent, a somewhat dubious
and frightening scale!), is Answer
.
. 1. about 20 megatons, similar to the most powerful hydrogen bombs.
.
.
. 2. similar to the first nuclear weapons—less than 10 kilotons.
.
.
. 3. greater than 1000 megatons.
.
.
. 4. about 1 megaton.
.
. 2 points
Question 48
. The Kuiper belt is Answer
.
. 1. a random distribution of short-period comets extending from inside the orbit of
. Jupiter
.
to approximately the orbit of Neptune.
.
.
. 2. another name for the asteroid belt.
.
.
.
. 3. a flat or donut-shaped distribution of distant comets around the Sun, extending out
. about
. 500 AU.
.
.
. 4. a spherical distribution of distant comets around the Sun, extending out about 50,000 AU.
.
. 2 points
Question 49
. What effect does Jupiter have on asteroids in the asteroid belt? Answer
.
. 1. Jupiter disturbs the orbits of all the asteroids in the belt, slowing them down and
. causing
.
them to spiral slowly in toward the Sun.
.
.
. 2. Jupiter perturbs only the orbits of asteroids whose orbital periods are a simple
. fraction
.
(e.g., 1/2, 1/3, 2/3, 2/7) of its orbital period.
.
.
. 3. Jupiter disturbs only the orbits of asteroids whose orbital distances (or semimajor axes)
. are. a simple fraction (e.g., 1/2, 1/3, 2/3, 2/7) of the radius of Jupiter's orbit.
.
.
. 4. Jupiter has no effect whatever on such small objects because they are a long way
. away
. from Jupiter, and Jupiter's gravitational influence varies as the inverse square
. of distance, by Newton's law.
. 2 points
Question 50
. Most meteorites show evidence of having melted or of being fragments of asteroids
that were once differentiated by heat. Carbonaceous chondrites, however, are
believed to have never melted. Which one of the following sentences is NOT a
reason we believe carbonaceous chondrites have never melted? Answer
.
. 1. Carbonaceous chondrites contain complex carbon compounds that would have
. been
. broken down into simpler compounds by high heat.
.
.
. 2. Carbonaceous chondrites do not show fusion crusts after passage through
. Earth's
.
atmosphere.
.
.
.
. 3.
.
.
. 4.
.
Amino acids that are occasionally found in carbonaceous chondrites would have
been
. destroyed by melting.
The minerals in carbonaceous chondrites contain as much as 20% water. The
water
. would have been driven out if the minerals had been heated.