Part 3

Question 1

The seasonal polar caps of Mars:

Answer 1

Are made mostly of carbon dioxide ice that forms and sublimates seasonally

Question 2

Global dust storms occur on Mars:

Answer 2

During southern spring and summer (dust storm season)

Question 3

How long is a solar day on Mars?

Answer 3

About 24 hours and 39 minutes

Question 4

The main constituent of the Martian atmosphere is:

Answer 4

Carbon dioxide (CO₂), about 95%

Question 5

The outflow channels on Mars indicate a flood period in the history of Mars. During this time, based on the width and depth of the remaining riverbed, it is thought that the flow rate must have been:

Answer 5

Extremely high, indicating catastrophic flooding

Question 6

Martian gullies are distinct from outflow channels in that:

Answer 6

They are much smaller and likely formed by more recent processes, possibly involving liquid water

Question 7

The atmospheric pressure on Mars:

Answer 7

Is very low — only about 1% of Earth’s surface pressure

Question 8

The permanent Martian north polar cap is composed of:

Answer 8

Water ice, with seasonal CO₂ frost cover in winter

Question 9

Presently, the most important agent of erosion and deposition on Mars is:

Answer 9

Wind

Question 10

The dendritic stream valleys on Mars:

Answer 10

Suggest that liquid water once flowed across Mars’ surface during its ancient past

Question 11

The atmospheric pressure on Mars is at its lowest when:

Answer 11

The seasonal polar caps are at their maximum size (winter at each pole)

Question 12

How does the global atmospheric circulation of Mars compare with that of the Earth and Venus?

Answer 12

Mars has large seasonal variations and strong cross-equatorial Hadley cells

Question 13

Compared with the Earth and Venus, the amount of greenhouse forcing on Mars’ surface temperature:

Answer 13

Is much weaker

Question 14

The permanent south polar cap of Mars:

Answer 14

Is smaller than the north cap and composed of a mix of water ice and frozen carbon dioxide

Question 15

Titan has a thick nitrogen-rich atmosphere with methane and hydrocarbon smog

Answer 15

True

Question 16

River channels on Titan are caused by:

Answer 16

Flowing liquid methane

Question 17

The surface of Titan is not visible from orbit due to:

Answer 17

A dense haze composed of complex hydrocarbons

Question 18

The temperature range within Titan’s atmosphere near the surface is such that:

Answer 18

Methane can exist as a liquid, solid, and vapor

Question 19

Due to the atmospheric pressure at the surface of Titan:

Answer 19

Wind plays a significant role in shaping the surface, including forming sand dunes

Question 20

Venus’ rotation:

Answer 20

Is very slow (243 Earth days) and retrograde

Question 21

What is the result of the Greenhouse effect on the surface environment of Venus?

Answer 21

It has raised the surface temperature by hundreds of degrees Celsius

Question 22

What is the composition of the clouds of Venus?

Answer 22

Sulfuric acid aerosols (H₂SO₄)

Question 23

The average atmospheric pressure at the surface of Venus:

Answer 23

Is about 92 bars, over 90 times that of Earth’s surface pressure

Question 24

Due to the extreme conditions at the surface of Venus:

Answer 24

Carbon dioxide exists as a supercritical fluid

Question 25

The surface temperature on Venus:

Answer 25

Is around 735 K (about 460°C or 860°F) and shows very little variation

Question 26

Wind speeds on Venus:

Answer 26

Are very high in the upper atmosphere (~100–240 km/h), but slow near the surface

Question 27

Large-scale atmospheric motion on Venus is determined by:

Answer 27

A balance between centrifugal forces and pressure gradient forces (cyclostrophic balance)

Question 28

Large-scale atmospheric motion on Venus is driven by:

Answer 28

The disparate heating between the equator and the poles

Question 29

Most of the solar energy is deposited on Venus:

Answer 29

In the upper cloud layers, not at the surface

Question 30

Atmospheric circulation on Venus is dominated by:

Answer 30

A single Hadley cell per hemisphere

Question 31

Based on the D/H ratio of the atmospheric water vapor on Venus:

Answer 31

It is thought that Venus lost most of its original water to space

Question 32

The temperature profile of Venus’ atmosphere:

Answer 32

Shows a steady decrease in temperature with altitude up to the tropopause

Question 33

The stratosphere of Venus’ atmosphere:

Answer 33

Does not have an ozone layer

Question 34

According to the Solar Nebula theory, planets:

Answer 34

Formed from a rotating disk of gas and dust around the young Sun

Question 35

As the terrestrial protoplanets grew in size, their strengthening gravitational fields led to what process?

Answer 35

Large-scale melting and differentiation (core formation)

Question 36

What is a distinguishing characteristic of planetesimals critical to planetary formation?

Answer 36

They were large enough for gravity to pull material together into larger bodies

Question 37

The formation of the solar system began with:

Answer 37

The gravitational collapse of a nebular cloud

Question 38

The solar nebula:

Answer 38

Was a rotating disk of gas and dust that formed the Sun and planets

Question 39

The last stages of planet formation:

Answer 39

Involved giant impacts between planetary embryos leading to the final four terrestrial planets