Question 1

What can we say about the abundance of volatile materials on Mercury?

Accepted Answer

A) The observed abundance of volatile materials is low. This is consistent with Mercury's formation close to the Sun, where volatile materials would be "boiled out" of the solar system. 
B) The observed abundance of volatile materials is low. This is consistent with a large planetesimal striking Mercury and taking away the outer mantle-the usual explanation for Mercury's large iron core. 
C) The observed abundance of volatile materials is low. This is consistent with the outer mantle of Mercury being stripped away in just a few minutes due to a large impact. 
D) The observed abundance of volatile materials is high. This is inconsistent with Mercury's formation close to the Sun. 
A) The observed abundance of volatile materials is low. This is consistent with Mercury's formation close to the Sun, where volatile materials would be "boiled out" of the solar system. 
B) The observed abundance of volatile materials is low. This is consistent with a large planetesimal striking Mercury and taking away the outer mantle-the usual explanation for Mercury's large iron core. 
C) The observed abundance of volatile materials is low. This is consistent with the outer mantle of Mercury being stripped away in just a few minutes due to a large impact. 
D) The observed abundance of volatile materials is high. This is inconsistent with Mercury's formation close to the Sun.

Question 2

The circulation pattern in Venus's atmosphere consists of:

Accepted Answer

A) one main convection cell in each of the northern and southern hemispheres, which extends from the equator almost to the poles and drives weaker cells above and below it. 
B) three cells in each of the northern and southern hemispheres, resulting from upwelling at the equator combined with the Coriolis force due to the planet's rotation. 
C) one main convection cell extending across the equator from near the pole in the "summer" hemisphere to subtropical latitudes in the "winter" hemisphere. 
D) several individual convection cells in regions where the time of day is noon to late afternoon, moving around the planet to keep pace with the Sun as Venus rotates. 
A) one main convection cell in each of the northern and southern hemispheres, which extends from the equator almost to the poles and drives weaker cells above and below it. 
B) three cells in each of the northern and southern hemispheres, resulting from upwelling at the equator combined with the Coriolis force due to the planet's rotation. 
C) one main convection cell extending across the equator from near the pole in the "summer" hemisphere to subtropical latitudes in the "winter" hemisphere. 
D) several individual convection cells in regions where the time of day is noon to late afternoon, moving around the planet to keep pace with the Sun as Venus rotates.

Question 3

How did optical illusion mislead early visual observers of Mars?

Accepted Answer

A) Apparent movement of surface features, because of fluctuations in images when viewed through Earth's atmosphere, were interpreted as evidence for moving life-forms or Martians. 
B) Volcano and rock structures were seen as eye shaped and face like and were interpreted as having been made by intelligent beings to indicate their presence. 
C) Moving areas of obscured detail on the planet were interpreted as massive flash floods rather than dust storms. 
D) Chance alignments of faint, dark features looked like canals whereas darker areas, when viewed against the orange-red surface, were interpreted as vegetation. 
A) Apparent movement of surface features, because of fluctuations in images when viewed through Earth's atmosphere, were interpreted as evidence for moving life-forms or Martians. 
B) Volcano and rock structures were seen as eye shaped and face like and were interpreted as having been made by intelligent beings to indicate their presence. 
C) Moving areas of obscured detail on the planet were interpreted as massive flash floods rather than dust storms. 
D) Chance alignments of faint, dark features looked like canals whereas darker areas, when viewed against the orange-red surface, were interpreted as vegetation.

Question 4

Phobos and Deimos, the two moons of Mars, rotate on their axes:

Accepted Answer

A) so that they always have the same sides facing each other as they orbit Mars. 
B) with no particular relationship to their revolutionary periods, that is, nonsynchronously. 
C) to maintain the same face toward the Sun at all times, because of tidal forces. 
D) synchronously, keeping one face toward Mars at all times. 
A) so that they always have the same sides facing each other as they orbit Mars. 
B) with no particular relationship to their revolutionary periods, that is, nonsynchronously. 
C) to maintain the same face toward the Sun at all times, because of tidal forces. 
D) synchronously, keeping one face toward Mars at all times.

Question 5

Venus and Earth are about the same size, yet they have only one of the following characteristics in common. Which one?

Accepted Answer

A) evidence of planet-wide plate tectonics 
B) volcanic activity 
C) a planet-wide magnetic field 
D) an atmosphere made up predominantly of greenhouse gases 
A) evidence of planet-wide plate tectonics 
B) volcanic activity 
C) a planet-wide magnetic field 
D) an atmosphere made up predominantly of greenhouse gases

Question 6

To what does the phrase "synchronous rotation" for an astronomical object (e.g., planet or moon) refer?

Accepted Answer

A) It has a rotation rate that is precisely maintained (e.g., 23 h 56 m 4.096 s for Earth). 
B) For an object in an elliptical orbit, the rotation rate increases and decreases to match the changes in its orbital speed. 
C) It completes precisely one rotation around its own axis for every orbit (1-to-1 spin-orbit coupling). 
D) It has any rotation period that is in simple proportion to its orbital period (1-to-1 spin-orbit coupling, 3-to-2 spin-orbit coupling, etc.). 
A) It has a rotation rate that is precisely maintained (e.g., 23 h 56 m 4.096 s for Earth). 
B) For an object in an elliptical orbit, the rotation rate increases and decreases to match the changes in its orbital speed. 
C) It completes precisely one rotation around its own axis for every orbit (1-to-1 spin-orbit coupling). 
D) It has any rotation period that is in simple proportion to its orbital period (1-to-1 spin-orbit coupling, 3-to-2 spin-orbit coupling, etc.).

Question 7

To explain the large iron core of Mercury, one theory suggests that as Mercury was forming as a planet it was struck by a large planetesimal, stripping away the mantle and leaving the iron core. This theory has the advantage because it also helps to explain Mercury's:

Accepted Answer

A) 3-to-2 spin-orbit coupling. 
B) highly elliptic orbit. 
C) Caloris Basin. 
D) slow rotation rate. 
A) 3-to-2 spin-orbit coupling. 
B) highly elliptic orbit. 
C) Caloris Basin. 
D) slow rotation rate.

Question 8

Mercury obeys Kepler's third law a3/T2 = 1. What is T in this equation?

Accepted Answer

A) Mercury's synodic period (in days) 
B) Mercury's synodic period (in years) 
C) Mercury's sidereal period (in days) 
D) Mercury's sidereal period (in years) 
A) Mercury's synodic period (in days) 
B) Mercury's synodic period (in years) 
C) Mercury's sidereal period (in days) 
D) Mercury's sidereal period (in years)

Question 9

The one terrestrial planet that rotates in the "wrong" direction (opposite to the planet's direction of revolution around the Sun) is:

Accepted Answer

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

Question 10

The original Mars landings were made by the Viking spacecraft in 1976 and 1977. The next three landers were Mars Pathfinder and the exploration rovers Spirit and Opportunity. What is the main advantage of these last three over the older Vikings?

Accepted Answer

A) The Vikings bounced along the Martian surface until they came to rest, whereas the more recent craft made soft rocket landings. 
B) The last three spaceships mounted cameras, while the Vikings had no cameras. 
C) The Vikings had to remain where they landed, but the more recent spaceships were able to explore far and wide across the surface. 
D) The Viking cameras were black and white, but the cameras on more recent spacecraft were color. 
A) The Vikings bounced along the Martian surface until they came to rest, whereas the more recent craft made soft rocket landings. 
B) The last three spaceships mounted cameras, while the Vikings had no cameras. 
C) The Vikings had to remain where they landed, but the more recent spaceships were able to explore far and wide across the surface. 
D) The Viking cameras were black and white, but the cameras on more recent spacecraft were color.

Question 11

Phobos, the innermost moon of Mars, has an orbital period that is less than 1 Martian day. This means that, as seen from Mars, Phobos appears to:

Accepted Answer

A) hover over one position all the time in a synchronous orbit. 
B) rise in the west, moving eastward. 
C) oscillate back and forth in the sky, never rising or setting from a given location. 
D) rise in the east, traveling westward. 
A) hover over one position all the time in a synchronous orbit. 
B) rise in the west, moving eastward. 
C) oscillate back and forth in the sky, never rising or setting from a given location. 
D) rise in the east, traveling westward.

Question 12

The clouds in the atmosphere of Venus consist primarily of:

Accepted Answer

A) dust particles. 
B) droplets of liquid methane and ammonia. 
C) droplets of H2SO4 or sulfuric acid. 
D) H2O. 
A) dust particles. 
B) droplets of liquid methane and ammonia. 
C) droplets of H2SO4 or sulfuric acid. 
D) H2O.

Question 13

When we view Mars at its most favorable opposition, a Martian would view Earth at:

Accepted Answer

A) most favorable opposition. 
B) least favorable opposition. 
C) superior conjunction. 
D) inferior conjunction. 
A) most favorable opposition. 
B) least favorable opposition. 
C) superior conjunction. 
D) inferior conjunction.

Question 14

There are several reasons the surface of Mars is more easily seen from Earth than any other planet's surface. Which of the following is NOT one of those reasons?

Accepted Answer

A) relative proximity to Earth 
B) high mountain ranges casting strong shadows and providing high-contrast images 
C) visible high in the sky at midnight when at opposition 
D) a thin, almost cloudless atmosphere 
A) relative proximity to Earth 
B) high mountain ranges casting strong shadows and providing high-contrast images 
C) visible high in the sky at midnight when at opposition 
D) a thin, almost cloudless atmosphere

Question 15

The "snow" that occasionally falls upon Mars and covers the bottoms of craters is most probably made of:

Accepted Answer

A) very fine white dust, disturbed occasionally by fierce wind storms. 
B) carbon dioxide ice. 
C) water ice. 
D) frozen sulfuric acid droplets. 
A) very fine white dust, disturbed occasionally by fierce wind storms. 
B) carbon dioxide ice. 
C) water ice. 
D) frozen sulfuric acid droplets.

Question 16

Judging by the density of craters, which of the following lists the planets according to the age of the surface from youngest to oldest?

Accepted Answer

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

Question 17

Which of these planets fits the following description: "a solid, cool surface, with occasional dust clouds and a thin CO2 atmosphere"?

Accepted Answer

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

Question 18

Each of the following supports the belief that large amounts of liquid water once existed on Mars EXCEPT one. Which is the exception?

Accepted Answer

A) Evaporites have been found on the surface. 
B) There is a deficiency of neutrons (produced in collisions of cosmic rays with rocks below the surface) escaping from the surface. 
C) Mud slides seem to follow some meteoric impacts. 
D) Scientists have found few carbonate rocks on Mars. 
A) Evaporites have been found on the surface. 
B) There is a deficiency of neutrons (produced in collisions of cosmic rays with rocks below the surface) escaping from the surface. 
C) Mud slides seem to follow some meteoric impacts. 
D) Scientists have found few carbonate rocks on Mars.

Question 19

What method was used to land the Mars Pathfinder spacecraft successfully on the Martian surface?

Accepted Answer

A) It was surrounded by balloons, similar to the airbags in automobiles, and allowed to bounce and roll to a stop, after impact on the planet. 
B) It was suspended beneath a large gas-filled balloon heated by sunlight allowing it to float in the atmosphere like a hot-air balloon until sunset, when it descended gently to the surface. 
C) Retro rockets were fired automatically to slow it to a safe landing speed as it neared the surface. 
D) It was flown down on a parachute similar to a hang glider to a smooth, if rather fast, landing. 
A) It was surrounded by balloons, similar to the airbags in automobiles, and allowed to bounce and roll to a stop, after impact on the planet. 
B) It was suspended beneath a large gas-filled balloon heated by sunlight allowing it to float in the atmosphere like a hot-air balloon until sunset, when it descended gently to the surface. 
C) Retro rockets were fired automatically to slow it to a safe landing speed as it neared the surface. 
D) It was flown down on a parachute similar to a hang glider to a smooth, if rather fast, landing.

Question 20

In examining the rocks on Mars, scientists have found all of the following EXCEPT one. Which rock type has NOT been found on Mars?

Accepted Answer

A) igneous rocks that appear to have been produced by volcanic action 
B) rocks resembling impact breccias like those in the lunar highlands 
C) layered rocks resembling the sedimentary rocks of Earth 
D) rocks containing chondrules (small glassy spheres) like those found in meteorites 
A) igneous rocks that appear to have been produced by volcanic action 
B) rocks resembling impact breccias like those in the lunar highlands 
C) layered rocks resembling the sedimentary rocks of Earth 
D) rocks containing chondrules (small glassy spheres) like those found in meteorites

Exam 11: Mercury, Venus, and Mars: Terrestrial, yet Unique

What can we say about the abundance of volatile materials on Mercury?

The circulation pattern in Venus's atmosphere consists of:

How did optical illusion mislead early visual observers of Mars?

Phobos and Deimos, the two moons of Mars, rotate on their axes:

Venus and Earth are about the same size, yet they have only one of the following characteristics in common. Which one?

To what does the phrase "synchronous rotation" for an astronomical object (e.g., planet or moon) refer?

To explain the large iron core of Mercury, one theory suggests that as Mercury was forming as a planet it was struck by a large planetesimal, stripping away the mantle and leaving the iron core. This theory has the advantage because it also helps to explain Mercury's:

Mercury obeys Kepler's third law a3/T2 = 1. What is T in this equation?

The one terrestrial planet that rotates in the "wrong" direction (opposite to the planet's direction of revolution around the Sun) is:

The original Mars landings were made by the Viking spacecraft in 1976 and 1977. The next three landers were Mars Pathfinder and the exploration rovers Spirit and Opportunity. What is the main advantage of these last three over the older Vikings?

Phobos, the innermost moon of Mars, has an orbital period that is less than 1 Martian day. This means that, as seen from Mars, Phobos appears to:

The clouds in the atmosphere of Venus consist primarily of:

When we view Mars at its most favorable opposition, a Martian would view Earth at:

There are several reasons the surface of Mars is more easily seen from Earth than any other planet's surface. Which of the following is NOT one of those reasons?

The "snow" that occasionally falls upon Mars and covers the bottoms of craters is most probably made of:

Judging by the density of craters, which of the following lists the planets according to the age of the surface from youngest to oldest?

Which of these planets fits the following description: "a solid, cool surface, with occasional dust clouds and a thin CO2 atmosphere"?

Each of the following supports the belief that large amounts of liquid water once existed on Mars EXCEPT one. Which is the exception?

What method was used to land the Mars Pathfinder spacecraft successfully on the Martian surface?

In examining the rocks on Mars, scientists have found all of the following EXCEPT one. Which rock type has NOT been found on Mars?

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

The Nature of Light

Optics and Telescopes

Comparative Planetology I: Our Solar System

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Jupiter and Saturn: Lords of the Planets

Jupiter and Saturns Satellites of Fire and Ice

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Cosmology: The Origin and Evolution of the Universe

Exploring the Early Universe

The Search for Extraterrestrial Life

Filters

Mercury obeys Kepler's third law a³/T² = 1. What is T in this equation?

Which of these planets fits the following description: "a solid, cool surface, with occasional dust clouds and a thin CO₂ atmosphere"?