Deck 7: Sibling Worlds: Mercury, Venus, and Mars

Question 1

If Mercury has water,it is most likely to be:

A) in its atmosphere.
B) in craters at the poles.
C) on the night side.
D) deep underground.

Answer 1

in craters at the poles.

Question 2

Mercury's long day-night cycle is a result of:

A) its position near the center of the Solar System.
B) tides.
C) its eccentric orbit.
D) all of the above.

Answer 2

its eccentric orbit.

Question 3

The search for water on Mars is an example of a:

A) guiding principle.
B) hypothesis.
C) paradigm.
D) test.

Answer 3

guiding principle.

Question 4

Which of the following phases occurred earliest in Earth's evolutionary process?

A) magma flooding
B) cratering
C) cooling
D) differentiation

Question 5

A terrestrial planet that forms in an environment with very few leftover planetesimals would differ from terrestrial planets in our Solar System because it would:

A) not have cooled as rapidly.
B) not have experienced magma flooding events.
C) have cooled more rapidly.
D) not have differentiated.

Question 6

Which of the following planets could NOT host features like that shown in the image below?

A) Mercury
B) Venus
C) Earth
D) Mars

Question 7

The terrestrial world most similar to Mercury is:

A) Venus.
B) Earth.
C) Earth's Moon.
D) Mars.

Question 8

An exoplanet is in a highly eccentric orbit with a semimajor axis of 0.4 AU.We expect it to have undergone:

A) tidal locking.
B) tidal synchronization.
C) neap tides.
D) spring tides.

Question 9

Mercury's iron content indicates that it may have:

A) strong magnetic fields.
B) retained much of its internal heat.
C) undergone a significant impact early in its history.
D) formed before the other terrestrial planets.

Question 10

Mercury's rapid cooling is responsible for its:

A) pronounced differentiation.
B) magnetic field.
C) linear cliff systems.
D) all of the above.

Question 11

The iron cores of terrestrial planets were formed:

A) during the earliest phase of planetary formation.
B) once the planets had cooled significantly.
C) during massive magma flooding events.
D) by planetesimals from the outer Solar System.

Question 12

Which terrestrial world has the least evidence for volcanism?

A) Mercury
B) Venus
C) Earth
D) Mars

Question 13

A "super-Earth" has a radius 1.4 times larger than Earth but an identical composition.How rapidly would it lose its internal heat energy compared to Earth?

A) The super-Earth would cool two times slower.
B) The super-Earth would cool 1.4 times slower.
C) The super-Earth would cool 1.4 times faster.
D) The super-Earth would cool two times faster.

Question 14

An exoplanet has a surface area nine times larger than Earth.All other factors being equal,how would the exoplanet's cooling time compare to Earth's?

A) nine times shorter
B) three times shorter
C) three times longer
D) nine times longer

Question 15

Nearly half of Mercury's volume is composed of:

A) solid iron.
B) basalt.
C) molten magma.
D) molten iron.

Question 16

Guiding principles help astronomers to:

A) generate theories in the absence of observations.
B) construct mathematical axioms.
C) identify the most important facts about an object.
D) exclude problematic observations from consideration.

Question 17

Two planets orbit a distant star.If the planets have identical compositions,the one that cools fastest would have the:

A) largest orbital semimajor axis.
B) smallest orbital semimajor axis.
C) largest planetary radius.
D) smallest planetary radius.

Question 18

Which of the following most closely resembles Mercury's surface?

A) the lunar maria
B) the lunar highlands
C) Olympus Mons
D) the Tharsis Bulge

Question 19

Mercury's magnetic field is produced by:

A) a dynamo.
B) the solar wind.
C) atmospheric motions.
D) fossil magnetism.

Question 20

Why does Mercury have a thin layer of hydrogen and helium as an atmosphere?

A) Other elements move fast enough to escape Mercury's gravity.
B) Mercury temporarily traps solar wind particles.
C) These are outgassed by rocks in Mercury's crust.
D) These gases are released during impacts with comets.

Question 21

Mars's interior has been studied through all of the following EXCEPT:

A) seismology.
B) rotational measurements.
C) magnetic fields.
D) density measurements.

Question 22

Which world has dome-like structures like those shown in the image below?

A) Venus
B) Mars
C) Mercury
D) Titan

Question 23

Planetary scientists have had difficulty understanding Venus's internal structure because it:

A) has not been geologically active.
B) rotates slowly.
C) has no moons.
D) has no cratering.

Question 24

About one billion years ago,Venus underwent a:

A) runaway greenhouse effect.
B) resurfacing following massive volcanism.
C) massive collision that dramatically slowed its rotation rate.
D) all of the above.

Question 25

The primary source of greenhouse gases on Venus is:

A) chemical reactions in the cloud layers.
B) asteroid and comet impacts.
C) volcanism.
D) evaporation.

Question 26

Which planet rotates in the opposite direction from which it orbits the Sun?

A) Jupiter
B) Mars
C) Neptune
D) Venus

Question 27

A planet's equilibrium surface temperature does NOT depend upon which of the following factors?

A) the planet's radius
B) the Sun's temperature
C) the planet's albedo
D) the planet's distance from the Sun

Question 28

A ball whose surface absorbs light is placed near a lightbulb.Suppose that the ball's temperature is affected only by the lightbulb and is initially 300 K.If the peak wavelength of the lightbulb doubled,what would the temperature of the ball be?

A) 300 K
B) 450 K
C) 500 K
D) 600 K

Question 29

Which terrestrial world experiences the strongest greenhouse effect?

A) Mercury
B) Venus
C) Earth
D) Mars

Question 30

Most likely,Venus's magnetic field is weak because it:

A) lacks a liquid metal core.
B) is deficient in iron.
C) rotates slowly.
D) is too close to the Sun's magnetic field.

Question 31

The polar caps of Mars are primarily composed of solid:

A) CO₂.
B) water ice.
C) methane.
D) salt.

Question 32

Suppose Earth were four times farther from the Sun.In the absence of the greenhouse effect,what would its temperature be? (You may assume that,without a greenhouse effect,Earth at its real location would have a temperature of 250 K.)

A) 16 K
B) 62 K
C) 125 K
D) 250 K

Question 33

Venus has very little water in its atmosphere in part because of:

A) chemical reactions in the cloud layer.
B) the rarity of asteroid and comet impacts on Venus.
C) its initial composition.
D) the solar wind.

Question 34

If some of the carbon dioxide in Venus's atmosphere were trapped by ground rocks,the planet would:

A) decrease in volcanic activity.
B) cool down.
C) become more blue.
D) become more magnetized.

Question 35

Which of the following has most strongly shaped Venus's surface?

A) weathering
B) cratering
C) volcanism
D) seismic activity

Question 36

Where is water ice most prominently found on present-day Mars?

A) throughout the surface rocks
B) underneath the northern polar cap
C) underneath both polar caps
D) nowhere; Mars is now dry

Question 37

Venus and Earth are nearly identical in their:

A) escape velocity.
B) orbital semimajor axis.
C) surface temperature.
D) rotation period.

Question 38

The principal component of Venus's atmosphere is:

A) carbon dioxide.
B) sulfuric acid.
C) water vapor.
D) nitrogen.

Question 39

In its composition,Mars's atmosphere most closely resembles that of:

A) Mercury.
B) Venus.
C) Earth.
D) none; Mars does not have an atmosphere.

Question 40

In which of the following respects does Mercury differ from all the other terrestrial worlds?

A) It is highly cratered.
B) It has a solid iron core.
C) It lacks evidence for substantial magma flows.
D) Its rotation period is comparable to its orbital period.

Question 41

What are the internal layers of Venus,from innermost to the surface? What is the primary composition of each one?

Question 42

On Mars,convection is most directly responsible for:

A) seasons.
B) crustal faulting.
C) weather.
D) magnetic fields.

Question 43

During the first 500 million years of its existence,Mars most closely resembled:

A) Earth.
B) the Moon.
C) Mercury.
D) Venus.

Question 44

Which planet's atmosphere is shown in the figure below?

Question 45

Why does Mercury lack a substantial atmosphere?

Question 46

The creation of the Tharsis Bulge was also responsible for:

A) lava domes.
B) outflow channels.
C) the Danilova crater.
D) the Valles Marineris system.

Question 47

Martian "blueberries" provide strong evidence for:

A) liquid water on Mars today.
B) subsurface water on Mars today.
C) liquid water in Mars's past.
D) biologic activity in Mars's past.

Question 48

How do astronomers use guiding principles to supplement the scientific method?

Question 49

The volcanic rocks on Mars are most similar to those from:

A) Earth's crust.
B) Earth's seafloor.
C) the Lunar highlands.
D) Earth's core.

Question 50

What is the correct ordering of the periods in Mars's history,from earliest to latest?

A) Noachian, Amazonian, Hesperian
B) Hesperian, Amazonian, Noachian
C) Hesperian, Noachian, Amazonian
D) Noachian, Hesperian, Amazonian

Question 51

How does the time required for a planet to lose its internal energy depend on its radius? Why?

Question 52

The image below shows the surface of a planet in our Solar System,which is covered by linear structures and craters similar to those shown here.Which one is it?

Question 53

If Mars had a Moon like Earth's,it would be more hospitable for the evolution of life because:

A) Mars has a stronger magnetic field.
B) Mars's obliquity is more stable.
C) Mars has suffered fewer impacts.
D) Mars's atmosphere is thicker.

Question 54

How would Earth change if it were moved to Mercury's orbit? Consider its atmosphere,internal structure,magnetic field,and day-night cycle.

Question 55

How are Mercury's orbital and rotation periods related to each other? Why?

Question 56

Other than Earth,the Solar System world with the most evidence for surface features affected by winds is:

A) Mars.
B) Venus.
C) Mercury.
D) Io.

Question 57

The origin of Mars's moons is:

A) capture of nearby asteroids.
B) ejecta from giant impacts.
C) fragmentation of a larger body.
D) currently an area of active investigation.

Question 58

What are the five phases of terrestrial planetary evolution,from earliest to latest?

Question 59

The figure below shows snapshots of a planet along its orbit around a star.This planet is experiencing changes in its:

A) eccentricity.
B) obliquity.
C) inclination.
D) oblateness.

Question 60

What is responsible for heating Venus's atmosphere to 730 K?

Question 61

How has Venus's high temperature affected its geology?

Question 62

Name two ways in which Phobos and Deimos differ from Earth's Moon.

Question 63

How did Venus's magnetic field soon after its formation compare to its magnetic field now? What,if anything,is responsible for any change?

Question 64

What two reasons are most important in explaining the different atmospheric compositions of Earth and Mars?

Question 65

Two identical planets orbit a star.Planet A has a semimajor axis of 2 AU,while planet B has a semimajor axis of 8 AU.If neither planet has an atmosphere,how do their surface temperatures compare?

Question 66

Compare the internal structure of Mars to that of Earth.

Question 67

How does the massive Olympus Mons volcano on Mars show that Mars does not undergo plate tectonics?

Question 68

What geographic features on Mars provide evidence for water on Mars?

Question 69

How do the volcanoes on Venus compare to those on Earth?

Question 70

Why did Mars become significantly less habitable about 500 million years after its formation?