AST FINAL

The physical model of the Sun's interior has been confirmed by observations of

a. neutrinos and seismic vibrations

b. sunspots and solar flares

c. neutrinos and positrons

d. sample returns from spacecraft e. sunspots and seismic vibrations

a

Sunspots, flares, prominences, and coronal mass ejections are all caused by

a. magnetic activity on the sun

b. electrical activity on the sun

c. the interaction of the Sun's magnetic field and the interstellar medium

d. the interaction of the solar wind and Earth's magnetic field

e. the interaction of the solar wind and the Sun's magnetic field

a

The structure of the sun is determined by both the balance between the forces due to ______ and gravity and the balance between energy generation and energy ______.

a. pressure; production

b. pressure; loss

c. ions; loss

d. solar wind; production

b

In the proton-proton chain, four hydrogen nuclei are converted to a helium nucleus. This does not happen spontaneously on Earth because the process requires

a. vast amounts of hydrogen

b. very high temperatures and densities

c. hydrostatic equilibrium

d. very strong magnetic fields

b

The solar neutrino problem pointed to a fundamental gap in our knowledge of

a. nuclear fusion

b. neutrinos

c. hydrostatic equilibrium

d. magnetic fields

b

Sunspots change in number and location during the solar cycle. This phenomenon is connected to

a. the rotation rate of the sun

b. the temperature of the sun

c. the magnetic field of the sun

d. the tilt of the axis of the sun

c

Suppose an abnormally large amount of hydrogen suddenly burned in the core of the Sun. Which of the following would be observed first?

a. the sun would become brighter

b. the sun would swell and become larger

c. the sun would become bluer

d. the sun would emit more neutrinos

a

The solar corona has a temperature of 1 million to 2 million Kelvin; the photosphere has a temperature of only about 6000 K. Why isn't the corona much, much brighter than the photosphere?

a. the magnetic field traps the light

b. the corona emits only x-rays

c. the photosphere is closer to us

d. the corona has a much lower density

d

The sun rotates once every 25 days relative to the stars. The sun rotates once every 27 days relative to Earth. Why are these two numbers different?

a. the stars are farther away

b. earth is smaller

c. earth moves in its orbit during this time

d. the sun moves relative to the stars

c

Coronal Mass Ejections

a. carry away 1 percent of the mass of the sun each year

b. are caused by breaking magnetic fields

c. are always emitted in the direction of Earth

d. are unimportant to life on Earth

b

As energy moves out from the sun's core toward its surface, it first travels by _______, then by, ________, and then by _______.

a. radiation; conduction; radiation

b. conduction; radiation; convection

c. radiation; convection; radiation

d. radiation; convection; conduction

c

Energy is produced primarily in the center of the Sun because

a. the strong nuclear force is too weak elsewhere

b. that's where neutrinos are created

c. that's where most of the helium is

d. the outer parts have lower temperatures and densities

d

The solar wind pushes on the magnetosphere of Earth, changing its shape, because

a. the solar wind is so dense

b. the magnetosphere is so weak

c. the solar wind contains charged particles

d. the solar wind is so fastest

c

When geologists place features in order from top to bottom, this determines

a. the relative size of features.

b. the origin of features.

c. the relative age of features.

d. the actual age (in years) of features.

c

Scientists can learn about the interiors of the terrestrial planets from
a. seismic waves
b. satellite observations of gravitational fields
c. physical arguments about cooling
d. satellite observations of magnetic fields
e. all of the above

e

Earth's interior is heated by
a. angular momentum and gravity
b. radioactive decay and gravity
c. radioactive decay and tidal effects
d. angular momentum and tidal effects
e. gravity and tidal effects

c

If a radioactive element has a half-life of 10,000 years, what fraction of it is left in a rock after 40,000 years?
a. 1/2
b. 1/4
c. 1/8
d. 1/16
e. 1/32

d

Lava flows on the moon and mercury created large, smooth plains. We don't see similar features on Earth because
a. Earth has less lava
b. Earth had fewer large impacts in the past
c. Earth has plate tectonics that recycle the surface
d. Earth is large compared to the size of these plains, so they are not as noticeable
e. Earth rotates much faster than either of these other worlds

c

Scientists know the history of Earth's magnetic fields because
a. The magnetic field hasn't changed since Earth formed
b. they see today's changes and project backward in time
c. the magnetic field becomes frozen into rocks, and plate tectonics spread those rocks apart
d. they compare the magnetic fields on other planets to Earth's

c

Suppose an earthquake occurs on an imaginary planet. Scientists on the other side of the planet detect primary waves but not secondary waves after the quake. This suggests that
a. part of the planet's interior is liquid
b. all of the planet's interior is solid
c. the planet has an iron core
d. the planet's interior consists entirely of rocky materials
e. the planet's mantle is liquid

a

Geologists can determined the actual age of features on a planet by
a. radiometric-dating of rocks retrieved from the planet
b. comparing cratering rates on one planet to those on another
c. assuming that all features on a planetary surface are same age
d. both a and b
e. both b and c

d

Impacts on the terrestrial planets and the Moon
a. are more common than they used to be
b. have occurred at approximately the same rate since the solar system formed
c. are less common than they used to be
d. periodically become more common and then less common
e. never occur anymore

c

Earth has fewer craters than Venus. Why?
a. Earth's atmosphere protects better than Venus's
b. Earth is a smaller target than Venus
c. Earth is closer to the asteroid belt
d. Earth's surface experiences more erosion

d

Scientists know that Earth was once completely molten because
a. the surface is smooth
b. the interior layers are denser
c. the chemical composition indicates this
d. volcanoes exist today

b

Scientists propose an early period of heavy bombardment in the Solar System because
a. the moon is heavily cratered
b. all the craters on the moon are old
c. the smooth part of the Moon is nearly as old as the heavily cratered part
d. all the craters on the moon are young

a

What is the main reason that Earth's interior is liquid today?
a. tidal force of the Moon on Earth
b. seismic waves that travel through Earth's interior
c. decay of radioactive elements
d. convective motions in the mantle
e. pressure on the core from Earth's outer layers

c

Mars has a diameter that is approximately half that of Earth. If the interiors of these planets are heated by radioactive decays, how does the heating rate of the interior of Mars compare to that of Earth?
a. The heating rate of Mars is 0.125 times that of Earth
b. The heating rate of Mars is 8 times that of Earth
c. The heating rate of Mars is 0.5 times that of Earth
d. The heating rate of Mars is 4 times that of Earth
e. The heating rates are about the same time

a

Categorizing moons by geological activity is helpful because
A) geological activity determines the size and composition of the moons.
B) most moons are very similar to each other.
C) geological activity levels drop with distance from the Sun.
D) comparing them reveals underlying physical processes.

d

Why are Ganymede and Callisto geologically dead while the other two Galilean moons of Jupiter are active?
A) they have retrograde orbits
B) they are more massive
C) they are farther from Jupiter
D) they are larger

c

Moons of outer planets may provide a home for life because
A) some have liquid water.
B) some have organic molecules.
C) some have an interior source of energy.
D) all of the above

d

Io has the most volcanic activity in the Solar System because
A) it is continually being bombarded with material in Saturn's E ring.
B) it is one of the largest moons and its interior is heated by radioactive decays.
C) of gravitational friction caused by the moon Enceladus.
D) the ice on the surface creates a large pressure on the water below.
E) its interior is tidally heated as it orbits around Jupiter.

e

Gravitational interactions with moons produce
A) smoothed-out rings.
B) short-lived rings.
C) fine structure within rings.
D) rings with spokes.

c

The story of the F Ring of Saturn is an example of
A)the self-correcting nature of science.
B) a violation of causality.
C) an unexplained phenomenon.
D) media bias.

a

If a moon revolves opposite to its planet's rotation, it probably
A) formed very recently in the Solar System history.
B) had its orbit altered by a collision.
C) was captured after the planet formed.
D) has a different composition from other moons.

c

Under what lighting conditions are the tiny dust particles found in some planetary rings best observed?
A) viewed from the near side of the planet, looking toward deep space
B) viewed from the shadowed side of the planet, looking toward deep space
C)viewed from the near side of the planet, looking toward the Sun
D)viewed from the shadowed side of the planet, looking toward the Sun

d

Planets in the outer Solar System have more moons than those in the inner Solar System because
A) the outer planets captured most of their moons.
B) there was more debris around the outer planets when they were forming.
C) there were more planetesimal collisions far from the Sun.
D) the solar wind was weaker there.

b

The difference between a moon and a planet is that
A)moons are smaller than planets.
B)moons and planets have different compositions.
C)moons orbit planets, whereas planets orbit stars.
D) moons and planets formed in different ways.

c

Scientists determine the geological history of the moons of the outer planets from
A) seismic probing.
B) radioactive dating.
C) surface features.
D) time-lapse photography.

c

The energy that keeps Io's core molten comes from
A) the Sun.
B) radioactivity in the core.
C) Jupiter's gravity.
D) residual heat from the collapse.

c

What influence do pairs of shepherd moons have on the giant planets' rings?
A) They keep rings between the pair narrow by gravitational tugs on the ring particles.
B) They only allow the rocky ring systems to remain stable while destabilizing the icy ring systems.
C)They cause the rings to eventually fall into Saturn by gravitational tugs on the ring particles.
D)They keep the rings systems completely stable forever.

a

Volcanoes on Enceladus affect the E Ring of Saturn by
A) stirring the ring particles.
B)dissipating the ring.
C) pushing the ring around.
D) supplying ring particles.

d

Mercury has (essentially) no atmosphere because

a. it's closer to the Sun, so its temperature is higher

b. it’s small
c. solar UV radiation breaks up molecules
d. all of the above

d

On which of these planets is the atmospheric greenhouse effect strongest?

a. venus
b. earth
c. mars

d.mercury

a

Earth's atmosphere is much different in composition than Venus's because

a. water is a liquid on the surface of Earth
b. the two planets' secondary atmospheres formed differently
c. Earth has had fewer impacts
d. Earth retained more of its primary atmosphere

a

If your body were not in hydrostatic equilibrium with the air, it would

a. swell or contract until equilibrium was reached
b. explode or collapse entirely
c. act as if it were in water, rising or falling depending on the pressure
d. accumulate or lose mass until it was back in equilibrium

a

The differences in the climates of Venus, Earth, and Mars are caused primarily by

a. the composition of their atmospheres
b. their relative distances from the sun
c. the thickness of their atmospheres
d. the time at which their atmospheres formed

a

Earth's magnetosphere

a. shields us from the solar wind
b. is essential to the formation of auroras
c. extends far beyond Earth's atmosphere
d. all of the above

d

Auroras do not happen on the moon because the moon

a. does not have a strong magnetic field
b. does not have an atmosphere
c. is protected from the solar wind by Earth
d. both a and b

d

The words weather and climate

a. mean essentially the same thing
b. refer to very different time scales
c. refer to very different size scales
d. both b and c

d

Studying climate on other planets is important to understanding climate on Earth because

a. underlying physical processes are the same on every planet
b. other planets offer a range of extremes to which Earth can be compared
c. comparing climates on other planets helps scientists understand which factors are important
d. all of the above

d

Less massive molecules tend to escape from an atmosphere more often than more massive ones because

a. the gravitational force on them is less
b. they are moving faster
c. they are more buoyant
d. they are smaller, and so experience fewer collisions on their way out

a

Venus is hot and Mars is cold primarily because

a. venus is closer to the sun
b. venus has a much thicker atmosphere
c. the atmosphere of venus is dominated by CO2, but the atmosphere of mars is not
d. venus has stronger winds

b

The atmosphere of mars is often pink-orange because

a. it is dominated by carbon dioxide
b. the sun is at a low angle in the sky
c. mars has no oceans to reflect blue light to the sky
d. winds lift dust into the atmosphere

d

Convection in the ________ causes weather on Earth

a. stratosphere
b. mesosphere
c. troposphere
d. ionosphere

c

Auroras are the result of

a. the interaction of particles from the sun and earth's atmosphere
b. upper-atmosphere lightning strikes
c. the destruction of stratospheric ozone, which leaves a hole
d. the interaction of Earth's magnetic field with Earth's atmosphere

a

Hadley circulation is broken into zonal winds by

a. convection from solar heating
b. hurricanes and other storms
c. interactions with the solar wind
d. the planet's rapid rotation

d

Earth experiences long-term climate cycles spanning about

a. 140,000,000 years
b. 140,000 years
c. 1,400 years
d. 140 years

b

Over the last 800,000 years, Earth's temperature has closely tracked

a. solar luminosity
b. oxygen levels in the atmosphere
c. the size of the ozone hole
d. carbon dioxide levels in the atmosphere

d

Uncertainties in climate science are dominated by uncertainty about

a. physical causes
b. current effects
c. past effects
d. future effects

a

Hydrostatic equilibrium is a balance between
a. heat and centrifugal force.
b. core temperature and surface temperature.
c. pressure and gravity.
d. radiation and heat.
e. centrifugal force and gravity.

c

The balance of energy in the solar interior means that
a. energy production rate in the core equals the rate of radiation escaping the Sun's surface.
b. the source of energy in the core is stable and will sustain the Sun for millions of years.
c. the outer layers of the Sun absorb and re-emit the radiation from the core at increasingly
longer wavelengths.
d. radiation pressure balances the weight of the overlying solar layers.
e. the core of the Sun has pressure that is higher than that of the outer layers.

a

Which force is responsible for holding the protons and neutrons in the nucleus of an atom together?
a. gravity
b. strong nuclear force
c. electric force
d. magnetic force
e. electrons pushing them together

b

The majority of the Sun's energy comes from
a. gravitational contraction.
b. nuclear fission of uranium.
c. hydrogen fusion.
d. helium burning.
e. burning material as in a fire.

c

What is the approximate temperature at the center of the Sun?
a. 106 K
b. 1.5 × 10^7 K
c. 2.5 × 10^7K
d. 10,000 K

b

The net result of the proton-proton chain of nuclear reactions is that four protons are converted into
a. one helium nucleus as well as energy, electrons, and neutrinos.
b. one helium nucleus as well as deuterium, electrons, and energy.
c. one helium nucleus, as well as energy, positrons, and neutrinos.
d. two helium nuclei, as well as neutrinos and positrons.

c

If the core of the Sun were hotter than it is now, how would the Sun's energy production change?
a. It would produce less energy per second than it does now.
b. It would produce more energy per second than it does now.
c. Its energy production would vary more than it does now.
d. Its energy production would be more stable than it is now.
e. The Sun's energy production would not change.

b

In the radiative zone inside the Sun, photons are transported from the core to the convective zone over a time
of
a. many thousands of years.
b. many millions of years.
c. seconds.
d. a few hours.
e. months.

a

Which of the following method(s) is (are) not used to transport energy from the core of the Sun to its surface?
a. radiation
b. convection
c. conduction
d. All of the above are important in the solar interior.
e. None of the above are important in the solar interior

c

Some restaurants place food under infrared heat lamps so that it stays warm after it has been cooked. This is
an example of energy being transported by
a. radiation.
b. convection.
c. conduction.
d. convection and conduction.
e. radiation and conduction.

a

The interior zones of the Sun are distinguished by
a. jumps in density between zones.
b. their temperature profiles.
c. pressure differences inside each zone.
d. their modes of energy transport.
e. all of the above

d

How does the fact that the surface of the Sun rings like a bell help us better understand the Sun?
a. The ringing tells us how quickly the Sun is expanding with time.
b. The ringing helps us understand the solar interior better.
c. The ringing reveals how rapidly the Sun's magnetic field is changing.
d. The ringing helps us determine the surface temperature of the Sun.

b

The detection of solar neutrinos confirms that
a. the Sun's core is powered by proton-proton fusion.
b. energy transport by radiation occurs throughout much of the solar interior.
c. magnetic fields are responsible for surface activity on the Sun.
d. convection churns the base of the solar atmosphere.
e. sunspots are cooler than the rest of the photosphere.

a

The hottest layer of the solar atmosphere is the
a. outer convection zone.
b. photosphere.
c. chromosphere.
d. corona.

d

The Sun's chromosphere appears red because
a. it is hotter than the photosphere.
b. as the Sun rotates, the chromosphere appears to move away from us radially.
c. it has a higher concentration of heavy metals.
d. it is made of mostly helium.
e. its spectrum is dominated by Hα emission.

e

In a sunspot, the umbra is
a. hotter than the penumbra.
b. cooler than the penumbra.
c. the same temperature as the penumbra.
d. less dense than the penumbra.

b

The solar magnetic field
a. returns to the same polarity every 11 years.
b. switches polarity every 22 years.
c. switches polarity every 11 years.
d. retains the same polarity during the entire solar activity cycle.

c

Which of the following are created by solar magnetic activity?
a. sunspots
b. prominences
c. coronal mass ejections
d. solar flares
e. all of the above

e

The magnetic field of the Sun is continuously produced and deformed by
a. its differential rotation.
b. the solar wind.
c. changes in the rate of nuclear fusion in the core.
d. a liquid conducting layer in the interior.
e. This is a trick question. The solar magnetic field is primordial.

a

If you observe a maximum number of sunspots right now, how long would you have to wait to see the next
solar maximum?
a. 24 hours
b. 6 months
c. 1 year
d. 11 years
e. 22 years

d

What makes extremophile organisms different from other life forms?

a. They can live in extreme conditions, such as very low or high temperature environments, oxygen-poor environments, or environments with extremely low light levels.

b. They live only in environments with extremely high temperatures, such as near volcanic vents.

c. They live in environments lacking in organic compounds.

d. They live in environments where little to no water is found, such as deserts.

a

Of what are Saturn's rings primarily made?
a. water ice
b. methane
c. nitrogen
d. dark organic material
e. dark silicate material

a

How do astronomers take such detailed, close-up pictures of ring systems?
a. They send satellites to the outer planets to take pictures for us.
b. They take them using backyard telescopes, just like Galileo did.
c. They take them using the largest optical telescopes on Earth.
d. They have astronauts in space take pictures of them.
e. They wait until the planet is closest to Earth and use the Hubble Space Telescope.

a

How do regular moons rotate in comparison to their planets?
a. in the same direction
b. in the opposite direction
c. sometimes in the same direction and sometimes in the opposite direction
d. Unlike their planets, moons don't rotate at all.

a

What influence do pairs of shepherd moons have on the giant planets' rings?
a. They keep the rings systems completely stable forever.
b. They only allow the rocky ring systems to remain stable while destabilizing the icy ring systems.
c. They cause the rings to eventually fall into Saturn by gravitational tugs on the ring particles.
d. They keep rings between the pair narrow by gravitational tugs on the ring particles

d

Most large regular moons probably formed
a. when passing asteroids were captured by the gravitational field of their planet.
b. at the same time as their planets and grew by accretion.
c. after a collision between a planet and a large asteroid fractured off a piece of the planet.
d. after the period of heavy bombardment in the early Solar System.
e. after a planet got kicked out of its orbit and was gravitationally captured by another planet.

b

Which of the following can be used as an indicator of the age of a moon's surface?
a. color of the surface
b. crater density
c. volcanic activity
d. radioactive dating
e. all of the above

e

Which of the following moons is thought to have a vast ocean of water beneath its frozen surface?
a. Triton
b. Europa
c. Ganymede
d. Io
e. Callisto

b

Io has the most volcanic activity in the Solar System because
a. it is continually being bombarded with material in Saturn's E ring.
b. it is one of the largest moons and its interior is heated by radioactive decays.
c. of gravitational friction caused by the moon Enceladus.
d. its interior is tidally heated as it orbits around Jupiter.
e. the ice on the surface creates a large pressure on the water below.

d

How do particles from the moon Enceladus wind up in Saturn's E ring?
a. Volcanoes erupt and expel silicates into space.
b. Water geysers erupt from the surface and expel them into space.
c. Cosmic rays bombard the surface rock on Enceladus and expel them into space.
d. A collision with a co-orbiting moon knocked rocky debris into orbit around Saturn.
e. Strong winds from Saturn blow material off of Enceladus's surface.

b

All of the following ring structures are known to be created by shepherd moons except
a. braided rings.
b. spokes.
c. scalloped edges.
d. ring gaps.
e. knots and kinks.

b

Cryovolcanism occurs when
a. molten lava freezes when it reaches the surface because of extremely low temperatures.
b. volcanoes erupt underwater.
c. an icy moon has volcanoes emitting molten lava from deep underground.
d. low-temperature liquids explode through the surface because of increasing pressure underground.
e. a comet hits an object and causes volcanic eruptions.

d

Which object has been turned inside out numerous times, leading to a situation where lighter elements have escaped, sulfur compounds compose the crust, and primarily heavier elements make up its core?
a. Mercury
b. Titan
c. Callisto
d. Pluto
e. Io

e

Which of the following moons do scientists believe most closely represents the primordial Earth, although at a much lower temperature?
a. Titan
b. Europa
c. Callisto
d. Io
e. Ganymede

a

What sort of liquids do astronomers believe exist on Saturn's moon, Titan?
a. Lakes of liquid nitrogen, N2
b. Lakes of normal water, H2O
c. Lakes of ammonia and hydrogen sulfide
d. Lakes of methane, ethane, and other hydrocarbons

d

If the Moon had active volcanoes,
a. the Moon would have a thick hydrogen atmosphere.
b. Earth might have a ring.
c. the Moon's surface would have more craters than it currently does.
d. life could not exist on Earth.
e. the Moon would have different phases than we see today.

b

Particles that make up the rings of Uranus and Neptune are composed of
a. rocky material from tidally disrupted moons.
b. organic material that has darkened because of bombardment by high-energy, charged particles.
c. icy material from tidally disrupted comets.
d. magma from volcanic eruptions on the surfaces of their moons.
e. all of the above

b

Which of the following processes did not contribute gas to Earth's secondary atmosphere?
a. volcanism
b. accretion
c. oxidation
d. comet impacts
e. All of the above contributed gases to Earth's secondary atmosphere.

c

The nitrogen in Earth's atmosphere primarily came from
a. ammonia delivered by comet impacts.
b. photosynthesis done by algae and plants.
c. oxidation of silicate-rich minerals.
d. rock delivered by asteroid impacts.
e. its primary atmosphere

a

Based solely on mass and distance from the Sun, which of the following terrestrial planets would you expect to retain the densest secondary atmosphere?
a. Mercury
b. Venus
c. Mars
d. the Moon
e. Earth

c

Earth has roughly _________ times more atmospheric pressure than Mars and _________ times less than Venus.
a. 10; 10
b. 200; 100
c. 2,000; 2
d. 2; 10
e. 1,000; 200

b