Deck 9: The Terrestrial Planets

Question 1

Which terrestrial planet is about one-third the size of Earth?

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

Answer 1

Mercury

Question 2

The Caloris Basin found on Mercury was probably formed by what process?

A) plate tectonics
B) an impact from a planetesimal
C) volcanic activity
D) erosion from solar wind

Answer 2

an impact from a planetesimal

Question 3

Mercury has only a trace atmosphere because

A) its close proximity to the Sun allows the Sun to gravitationally pull gases directly off the surface of Mercury.
B) impacts from planetesimals caused its original atmosphere to evaporate away.
C) its slow rotation allows atmospheric gases to escape the planet.
D) its smaller size means it has gravitational attraction that is too weak to hold onto an atmosphere.

Answer 3

its smaller size means it has gravitational attraction that is too weak to hold onto an atmosphere.

Question 4

Which planet shows the largest variation of day and night temperatures?

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

Question 5

The surface of Mercury resembles the Moon's surface in that they are both ______.

A) eroded by wind
B) newly resurfaced
C) heavily cratered
D) covered with volcanoes

Question 6

Of all the terrestrial planets, ______ has the largest daily temperature variation.

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

Question 7

Mercury's average density is about as high as Earth's. This is most likely because

A) it contains a significantly higher fraction of iron than Earth.
B) it is highly compressed by its own gravity.
C) it is composed of material blasted off Earth in a collision.
D) unlike Earth, it does not have a (light) atmosphere that lowers its average density.

Question 8

Mercury's crust

A) is molten because it is so close to the Sun.
B) may have been mostly lost after a collision with a large planetesimal.
C) is much thicker than Earth's or Venus.'
D) has an unusually high concentration of silicate rocks.

Question 9

Mercury features long, steep cliffs in its crust called "scarps" which probably formed

A) after impacts from a planetesimal or asteroid.
B) from floods of running water left to evaporate after comet impacts.
C) as plates of crust shifted as a result of massive earthquakes at a fault.
D) like giant wrinkles as the crust cooled and shrank.
E) by erosion from high solar winds.

Question 10

What is the surface of Mercury like?

A) rocky, with craters and scarps
B) rocky, with volcanoes and old ocean basins
C) gaseous
D) mostly rock, but covered about 40% by liquid methane

Question 11

Which surface feature of the Moon is not found on Mercury?

A) craters
B) maria
C) rays
D) mountains

Question 12

Why is the surface of Mercury more level (flatter) than the surface of the Moon?

A) Mercury has stronger gravity and had a hotter interior.
B) Heat from the Sun made Mercury's surface softer and more malleable.
C) The Moon formed out of the debris from a collision of two larger bodies.
D) Tidal forces from Earth have pulled the Moon out of shape.

Question 13

How did Mercury's chaotic terrain form?

A) A hot spot in Mercury's crust generated earthquakes, which jumbled the surface material.
B) Earthquake waves from the impact that formed Caloris Basin heaved up the rock in this region.
C) Many impacts in that region created the feature, and it was never smoothed over by lava flows.
D) Tidal stresses from Mercury's elliptical orbit have wrinkled that part of the surface.

Question 14

What does Mercury most resemble in size and appearance?

A) Venus
B) Mars
C) the Moon
D) Earth

Question 15

Does Mercury have an atmosphere? Why or why not?

A) Yes. Mercury has a substantial atmosphere of solar hydrogen and helium.
B) Yes, but it is only one-tenth the atmosphere of Venus.
C) It has only traces of gases temporarily captured from space, as well as material outgassing from the surface.
D) Astronomers have not been able to tell so far.

Question 16

Why is the nightside of Mercury so much colder (relatively speaking) than the dayside?

A) Mercury is in synchronous rotation, so the far side of Mercury never sees the Sun.
B) Mercury's small size lets it cool quickly.
C) Mercury's slow rotation gives the nightside plenty of time to release its heat.
D) Mercury's magnetic field acts like a blanket on the planet's dayside.

Question 17

Why is the nightside of Mercury so much colder (relatively speaking) than the dayside?

A) Mercury is in synchronous rotation, so the far side of Mercury never sees the Sun.
B) Mercury's small size lets it cool quickly.
C) Mercury's lack of an atmosphere keeps the planet from retaining its surface heat.
D) Mercury's magnetic field acts like a blanket on the planet's dayside.

Question 18

Ice has been discovered at Mercury's poles. How can it survive, given the planet's dayside temperature?

A) Mercury's small size let the planet cool quickly.
B) Mercury has an elliptical orbit that carries it far from the Sun.
C) Parts of Mercury's poles are in permanent shadow.
D) Mercury rotates such that one side of the planet always faces the Sun.

Question 19

Mercury's average density is about 50% greater than the Moon's, even though the two bodies have similar radii. This suggests that Mercury('s)

A) interior is much richer in iron than the Moon's.
B) contains proportionately far more rock than the Moon.
C) greater mass has prevented its gravitational attraction from compressing it as much as the Moon's is.
D) must have a liquid water core.

Question 20

Why was the discovery of Mercury's liquid core a surprise to scientists?

A) Mercury's small size should have allowed it to cool early in its history.
B) Mercury's magnetic field was too weak to be generated by a liquid core.
C) Mercury's density suggested that there should have been a small solid core.
D) Mercury's rotation was too slow to sustain a liquid core.

Question 21

Why is Mercury's magnetic field so weak, relative to Earth's?

A) Mercury has a solid core that cannot sustain a strong field.
B) Mercury's rotation is too slow to generate a strong field.
C) Mercury has a very small iron core that cannot sustain a strong field.
D) Mercury's dayside temperature is too high for a strong field to form.

Question 22

What is the effect of resonance on Mercury's rotation?

A) Mercury shows the same face to the Sun when Mercury is closest to it.
B) Mercury spins three times on its axis for every two orbits.
C) Mercury's spin has slowed down.
D) All of these choices are correct.

Question 23

Which planet has the hottest surface temperature?

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

Question 24

Which planet has a greenhouse effect?

A) Mercury
B) Venus
C) Earth
D) Mars
E) Venus, Earth, and Mars

Question 25

Which of the other terrestrial planets is closest in size to Earth?

A) Mars
B) Venus
C) Mercury
D) the Moon

Question 26

The atmosphere of Venus consists mainly of ______.

A) carbon dioxide
B) sulfuric acid
C) nitrogen and oxygen
D) carbon monoxide
E) hydrogen and helium

Question 27

The clouds of Venus consist mainly of ______.

A) carbon dioxide
B) water vapor
C) hydrogen and helium
D) sulfuric acid
E) carbon monoxide

Question 28

The surface of Venus is dominated by _____.

A) impact craters
B) recent lava flows
C) scarps
D) large canyons
E) oceans of sulfuric acid

Question 29

Venus's extremely high surface temperatures are due to

A) the composition of its atmosphere.
B) volcanic activity.
C) its relatively close proximity to the Sun.
D) a recent impact that heated the planet.

Question 30

Maps of Venus have been made by

A) landing spacecraft on the surface to take pictures.
B) bouncing radio waves off the planet from satellites and Earth.
C) optical telescopic observations from Earth when the clouds part.
D) measuring seismic waves from earthquakes.

Question 31

You would most likely find pancake-shaped lava domes on

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

Question 32

The atmosphere of Venus is 95% ____.

A) water vapor
B) sulfuric acid
C) carbon dioxide
D) hydrogen

Question 33

Where in Venus's atmosphere are sulfuric acid clouds found?

A) near the surface, like fog
B) at very high altitudes
C) everywhere in the atmosphere
D) There are no sulfuric acid clouds on this planet.

Question 34

What drives the high-speed winds in Venus's atmosphere?

A) light from the Sun in its equatorial regions
B) cold temperatures at the poles
C) the slow spin of the planet
D) a polar vortex

Question 35

Despite its thick cloud cover, astronomers can observe the surface of Venus with

A) visible light.
B) infrared light.
C) ultraviolet light.
D) radar.

Question 36

The polar vortex at the south pole of Venus is

A) a high-pressure zone with winds flowing away from its center.
B) a region where cooler gases sink to the surface before moving back to the equatorial regions.
C) a region of the atmosphere where the surface can be seen from orbit.
D) a low-pressure, high-humidity storm, much like a hurricane on Earth.

Question 37

What are the clouds of Venus mainly composed of?

A) methane
B) water vapor
C) sulfuric acid droplets
D) carbon dioxide

Question 38

Why is Venus's surface hotter than Mercury's?

A) Venus rotates more slowly, so it "bakes" more in the Sun's heat.
B) Clouds in Mercury's atmosphere reflect sunlight back into space and keep its surface cool.
C) Carbon dioxide in Venus's atmosphere traps heat radiating from its surface, thereby making it warmer.
D) Venus is closer to the Sun.

Question 39

The runaway greenhouse effect on Venus is most directly responsible for which planetary characteristic?

A) the planet's retrograde rotation
B) the absence of water on Venus
C) the absence of a planetary magnetic field at Venus
D) Venus's polar vortex

Question 40

Which characteristic of Venus is not due to the runaway greenhouse effect?

A) surface temperatures that are higher than Mercury's
B) thick lava that creates pillow-shaped domes
C) a very slow rotation rate
D) clouds that completely hide the surface

Question 41

Brief increases in atmospheric sulfur in Venus's atmosphere may be due to

A) a large meteor entering Venus's atmosphere.
B) a volcanic eruption on Venus's surface.
C) cloud-to-cloud lightning in Venus's atmosphere.
D) chemical reactions between sulfuric acid clouds and the surface.

Question 42

Why is Venusian lava less viscous than Earth's?

A) There is more water in Earth's lava.
B) Earth's surface has a lower temperature.
C) Atmospheric pressure on Venus is much higher than on Earth.
D) Earth's rapid rotation stirs its lava, making it thinner.

Question 43

Venus's crust is thicker than Earth's because

A) Venus has little internal activity, keeping the crust from melting.
B) rocks on Venus melt at higher temperatures.
C) the high temperatures at the surface of Venus have baked the crust.
D) volcanic eruptions continuously add more material to the surface.

Question 44

The slow, retrograde spin of Venus is responsible for which phenomenon on Venus?

A) the polar vortex
B) high-speed upper atmospheric winds
C) Mercury is a permanent "morning star."
D) The Sun rises in the west and sets in the east.

Question 45

The red coloration seen on the Martian surface originates from

A) past volcanic activity covering the surface of the planet with red lava.
B) when Mars' had flowing water, it also has red algae, which stained the surface rocks.
C) the atmosphere blocking out blue light, only allowing red light to reflect off the surface.
D) the iron minerals in the surface rocks combining with oxygen in the atmosphere causing the surface to rust.

Question 46

Which planet is about half the size of Earth?

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

Question 47

Besides Earth, which terrestrial planet also has seasons?

A) Mercury
B) Venus
C) Mars
D) Seasons are unique to Earth.

Question 48

The Valles Marineris is ______ on the surface of Mars.

A) an old riverbed
B) a 4,000-km canyon
C) a long scarp
D) a large volcano

Question 49

The atmosphere of Mars consists mainly of ______.

A) carbon dioxide
B) carbon monoxide
C) nitrogen
D) oxygen

Question 50

Mars' axial tilt and spin are most similar to _____.

A) Earth's
B) Mercury's
C) Venus's
D) the Moon's

Question 51

Evidence that there is a considerable amount of water frozen under the surface of Mars is provided by all of the following except

A) squishy-looking flow patterns around crater impact sites.
B) features resembling channels cut by flowing water.
C) periodic eruptions of geysers when subsurface ice is melted by volcanic activity.
D) discovery by the Mars rovers of chemicals in surface rocks formed in the presence of large amounts of water.
E) satellite measurements of water in the polar caps.

Question 52

Mars experiences a sequence of seasons similar to Earth's. Why?

A) Mars's distance from the Sun is about the same as Earth's.
B) Mars's axial tilt is almost the same as Earth's.
C) Mars has polar ice caps, much like Earth's.
D) Mars experiences gravitational forces from its moons, just as Earth does.

Question 53

Which group contains only features that can be seen on the surface of Mars?

A) canyons, oceans, volcanoes, polar caps
B) craters, canyons, polar caps, volcanoes
C) polar caps, oceans, dried up riverbeds
D) All of these choices are correct.

Question 54

Olympus Mons is

A) a volcano on Mars.
B) the largest mountain on Earth.
C) a Mars observatory in Greece.
D) one of Mars's moons.

Question 55

The slopes of Olympus Mons are relatively free of impact craters. What does this imply about its history?

A) Olympus Mons has erupted in the last 250 million years.
B) The mountain is tall enough to be eroded by planetary dust storms.
C) It is one of the oldest features on Mars.
D) Olympus Mons was once submerged in water.

Question 56

How do the Martian polar caps differ from Earth's?

A) They change size and shape with the seasons.
B) They are composed of frozen water and carbon dioxide.
C) They contain a large fraction of the planet's water.
D) They contain a record of the planet's climate history.

Question 57

The Martian polar caps are composed of frozen

A) water and carbon dioxide.
B) water and methane.
C) methane and carbon dioxide.
D) water and sulfuric acid.

Question 58

Of these, which is evidence that Mars once had running water on its surface?

A) There are vast amounts of H₂O present in Martian rocks.
B) There is medium-sized ocean in the Southern Hemisphere of Mars.
C) Spacecraft have observed channels and dry riverbeds on the Martian surface.
D) There is no such evidence.

Question 59

Some recent evidence points to the possibility of there being some liquid water on Mars "recently." Why does this puzzle astronomers?

A) Currently Mars is too hot for liquid water.
B) The Martian atmosphere is too thick, and clouds would form.
C) The Martian atmosphere is too cold and has too low a pressure for liquid water.
D) All of these choices are correct.

Question 60

A cupful of liquid water placed on the surface of Mars would

A) quickly freeze into solid ice.
B) quickly boil and evaporate.
C) expand rapidly and shatter.
D) rapidly cool but remain liquid.

Question 61

Why did the discovery of Martian "blueberries" suggest the presence of water on Mars?

A) Plant life must have water to grow.
B) "Blueberries" on Earth form by the deposition of minerals in water.
C) They were found in an ancient seafloor on Mars.
D) None of these choices is correct.

Question 62

Other than in the polar caps, any remaining water on Mars is likely stored as

A) frost on the surface of the planet.
B) clouds high in the atmosphere of the planet.
C) permafrost beneath the surface of the planet.
D) mists in the equatorial regions of the planet.

Question 63

If Mars had liquid water on its surface in the distant past, then its atmosphere must have been ____ than it is now.

A) warmer
B) wetter
C) denser
D) All of these choices are correct.
E) None of these choices is correct.

Question 64

Mars's atmosphere is most similar in composition to the atmosphere of ____.

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

Question 65

Why is the greenhouse effect weaker on Mars than on Earth or Venus?

A) There is no carbon dioxide in Mars's atmosphere.
B) Mars's atmosphere is much thinner than those of Venus and Earth.
C) High water vapor clouds reduce the amount of sunlight that reaches the planet's surface.
D) Fog and frost on the Martian surface reflect much of the Sun's energy.

Question 66

Mars spins on its axis at approximately the same speed as Earth, yet it has no magnetic field.Why not?

A) Mars has no iron core.
B) Mars is small and cooled quickly.
C) Mars is farther from the Sun than Earth is.
D) None of these choices is correct.

Question 67

The moons of Mars are

A) Phobos and Deimos.
B) captured asteroids.
C) too small to pull themselves round.
D) All of these choices are correct.

Question 68

What features are unique to Earth?

A) canyons
B) volcanoes
C) an atmosphere
D) precipitation
E) None of these features is unique to Earth.

Question 69

List the terrestrial planets in increasing order of their size.

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

Question 70

On which planet does plate tectonics take place?

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

Question 71

Which of the terrestrial planets does not have any craters?

A) Mercury
B) Venus
C) Earth
D) Mars
E) All of them have craters.

Question 72

List the terrestrial planets in decreasing order of their mass.

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

Question 73

Which terrestrial planet is tilted upside down?

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

Question 74

Which of the terrestrial planets have the most similar atmospheric compositions?

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

Question 75

Which of the following statements correctly compares the terrestrial planets?

A) Venus has the densest atmosphere and the highest average temperature.
B) Earth is the only planet that has active plate tectonics and surface water.
C) Mercury is the planet with the thinnest atmosphere and the smallest size.
D) All of these choices are correct.

Question 76

______ is the smallest of the terrestrial planets.

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

Question 77

______ is the largest of the terrestrial planets.

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

Question 78

Mercury's ________ and, therefore, the planet does not have seasons.

A) axial tilt is zero
B) orbit is too close to the Sun
C) atmosphere is almost nonexistent
D) orbit is a perfect circle

Question 79

Which reason best explains why both Venus' and Mars' atmospheres are primarily carbon dioxide, but Earth's is much less than 1% carbon dioxide?

A) Earth's rocks had much less carbon and oxygen in them.
B) Venus and Mars, being smaller than Earth, can't retain the same mixture of gases as Earth.
C) Each planet has a significantly different surface temperature.
D) Plant life has existed on Earth for an extended amount of time.

Question 80

Why do Earth and Venus have active interiors, while Mercury and Mars do not?

A) Mercury and Mars have small iron cores, while Earth and Venus have large ones.
B) Earth and Venus are much more massive, and cool more slowly, than Mars and Mercury.
C) Earth and Venus have rapid rotations, while Mercury and Mars do not.
D) All of these choices are correct.
E) None of these choices is correct.