Unit 5

Question 1

What are the 4 gas giants in our solar system?

Answer 1

Jupiter, Saturn, Uranus, Neptune

Question 2

What are the common features shared by the gas giants?

Answer 2

All have an atmosphere of hydrogen and helium, more H than He. Have cores that are called “rocky”. Surrounded by systems of rings and natural satellites. Lastly they all rotate fast (Jupiter being the fastest)

Question 3

How/when do the gas giants form?

Answer 3

All those volatile and liquid elements that would be given off by an early star would gather quickly into frozen blobs in the cold outer reaches of the system, where they would grow and their gravitational attraction would increase, they’d start pulling greater and greater quantities of volatiles and liquids into themselves

Question 4

What did we learn by watching the Shoemaker-Levy 9 comet impacting Jupiter?

Answer 4

It was the first known Jupiter-orbiting comet, it caused a change in Jupiters environment.

Question 5

How do we know that Jupiter is big?

Answer 5

Its 3x bigger than Saturn, could fit more than 1000 Earth’s inside

Question 6

How do we know that it is hot? Why does it have a high heat flow (what is the internal heat engine)?

Answer 6

It emits about 1.7x as much energy as it receives from the Sun

Question 7

Describe what we observe happening on Jupiter’s surface. What energy is driving the turbulence in the atmosphere? How does this differ from how weather patterns are driven on Earth? What is the Great Red Spot?

Answer 7

Probably heat escaping from the deep interior of the planet. Weather patterns on Jupiter appear to be dominated by the interior, while Earths is driven from above(the Sun). The GRS is the largest dark spot

Question 8

Why did scientists crash the Galileo spacecraft into the surface of Jupiter? What did we learn during this descent?

Answer 8

If it wasn’t done some of its discoveries would have been contaminated, we learned that it may have a salt water ocean and may contain microbial life

Question 9

Jupiter is primarily composed of hydrogen in various states (e.g. gas, liquid etc.) Describe the structure of the planet (e.g. Fig 14.6). Does the liquid hydrogen ocean have a surface?

Answer 9

From a true gaseous hydrogen-rich atmosphere it turns into liquid hydrogen then to ‘metallic’ hydrogen and finally a heavy metal core. It doesn’t have a surface

Question 10

Does Jupiter have a magnetic field? How might it be formed?

Answer 10

Yes, strongest of all the planets in the Solar System, it efficiently traps electrically charged particles (from the solar wind) and shapes them into a teardrop form of magnetosphere of radiation around the planet

Question 11

How does the magnetic field interact with the solar wind and what implications does this have for life (e.g. humans visiting the planet or alien life on the moons of Jupiter)?

Answer 11

It would be deadly to humans, equivalent of a billion chest X-rays

Question 12

Explain how the dark belts and bright zones form in Jupiter’s atmosphere.

Answer 12

A result of the high rate of rotation of the planet, cool material will sink in the belt and warm material rises in the zone

Question 13

What are the 3 classification of satellites (for Jupiter’s satellites and elsewhere)? Compare the characteristics/formation/orbits of each kind.

Answer 13

Regular, Irregular and Trojan. Facts are in the vocab section

Question 14

What are the 3 principles in comparative planetology?

Answer 14

1. Body’s composition depends on the temperature of the material from which it formed. Illustrated by the prevalence of ice as a building material in the outer Solar System where sunlight is weak
2. Cratering tells us the age of a hard surface
3. Internal heat has a powerful influence over the geology of larger satellites

Question 15

Compare the structure of these 4 main satellites to each other with particular attention to how the size of the satellite and its proximity to Jupiter determine:

a. If the body is differentiated (related to heat source, which varies among satellites)
b. If there is a liquid core (and consequently a magnetic field)
c. If there is an atmosphere
d. The density/composition of the satellite

Answer 15

??

Question 16

Why do Europa and Io have few craters (two different reasons)?

Answer 16

Must be “resurfaced” periodically and ash/lava buries new craters

Question 17

Which of these satellites might have some possibility of supporting life? Why?

Answer 17

Europa, researchers suggest that enough oxygen could build up in Europa’s oceans to support microbes, or even larger life forms

Question 18

Why is it hard to view Saturn’s surface?

Answer 18

Thick high altitude haze layer

Question 19

How did the Cassini Huygens spacecraft get enough energy to reach Saturn’s orbit?

Answer 19

Dependent upon the gravity assists received from other Solar System bodies + a small plutonium nuclear reactor fuel cell, which didn’t endear this craft to environmental activists

Question 20

Why is Saturn less dense than Jupiter?

Answer 20

There is less hydrogen(lightest element) and more elements that are heavier

Question 21

What is the interior structure of Saturn (e.g. core and various layers)

Answer 21

Has a small rocky core, a thicker metallic hydrogen inner mantle and the rest is mostly liquid hydrogen with an outermost 1000km thick layer of atmosphere

Question 22

What is causing Saturn to generate heat?

Answer 22

Friction of the falling droplets and the Compaction of them in the core heat the planet

Question 23

Why is there no clear division between the atmosphere and the surface of the planet?

Answer 23

There is no “surface”, its just a slow gradual change form a gaseous atmosphere to a liquid planet

Question 24

What are the 2 main components of Saturn’s atmosphere?

Answer 24

Mostly hydrogen and then some helium

Question 25

Explain the 3 levels of cloud formation on Jupiter and Saturn. On which planet are the clouds higher in the atmosphere and why?

Answer 25

Belt zone, Zones - clouds are higher by rising gas in saturn, and Belts - clouds are lower by sinking gas in saturn

Question 26

Does Saturn have a magnetic field? If so, what causes it?

Answer 26

Yes, its perfect symmetrical. Dynamo is probably an interaction between the core and metallic hydrogen inner mantle

Question 27

What are the gaps in Saturn’s rings?

Answer 27

??

Question 28

What are the rings composed of? Do other gas giants have rings? Compare differences in
formation of rings among the gas planets.

Answer 28

95% water ice, more dirt than ice in the gap. Yes all gas giants have rings. ???

Question 29

Why are the rings orbiting Saturn’s equator rather than spread in a haze about the whole planet?

Answer 29

A body orbiting around Saturn’s equatorial zone “feels” a greater gravitational pull than when it passes over the polar regions because there is more material below it

Question 30

Do we know what causes the appearance of “spokes” on the B ring?

Answer 30

Dark radial features that move in curious patterns on the B ring??

Question 31

Do collisions of particles in the rings make particles larger or smaller? Explain.

Answer 31

Gentle collisions grinds down the larger particles, while smallest particles tent to stick together with accretion

Question 32

Outline the evidence that suggests the material in Saturn’s rings is young.

Answer 32

Ice blocks were very reflecting and fresh looking, almost no dust on their surfaces, suggesting they aren’t old. Water ice in the near-vacuum of space would deteriorate over time by sublimation

Question 33

What about the argument that suggests the rings might be old?

Answer 33

Rings were ancient and probably made at the time Saturn accreted

Question 34

What is a possible source of the water/ice in the rings?

Answer 34

Rings were once a satellite of Saturn whose orbit decayed until it came close enough to be ripped apart by the tidal force interaction, water ice outer sheath of the satellite disintegrated and formed rings while the rock core dropped to the planet

Question 35

What is the composition of Titan’s atmosphere?
Is the surface hot or cold? What is special about the volcanic activity on Titan? What is the source of methane in the atmosphere on Titan vs. Earth? What are Titan’s dunes composed of? Does Titan have the ingredients required for life?

Answer 35

Composed of mainly nitrogen. The surface is cold! Volcanoes spew out cool-cold water and ices. ____. Dunes are composed of sand. Yes it does

Question 36

Which of Saturn’s satellites looks like the Death Star from the Star Wars movies?

Answer 36

Mimas

Question 37

What processes result in Enceladus having liquid water at the surface?

Answer 37

Kneading and the wobble should produce just enough heat to make liquid water

Question 38

What is a shepherd satellite and how do they stabilize rings?

Answer 38

Small satellites associated with the rings were thought to act as ring stabilizers, will orbit Saturn just barely outside the ring with which it’s associated and the gravitational force of the satellite will drag the particles back toward it, controlling the energy of the particles and temporarily stabilizing their orbit

Question 39

Why are Uranus and Neptune considered “ice giants”?

Answer 39

Uranus and Neptune have much higher proportions of water, ammonia and methane than hydrogen and helium. Water, ammonia and methane are considered “ices”

Question 40

Do these planets have rings? What might be the source of material for the rings?

Answer 40

Yes, It’s thought they were generated by impacts of small satellites or by the disintegration of a comet

Question 41

Contrast the internal heat of these two planets. Why might Uranus be cold? Where does Neptune’s heat originate?

Answer 41

Uranus has to lowest heat signature, radiating exactly the same amount of heat that it receives from the Sun. Neptune has more, it may be generated by radioactive decay in the rock minerals in its interior, it radiates 2.61z as much heat as it receives from the sun

Question 42

Neither Uranus nor Neptune can be seen from Earth with the naked eye – Explain (in general) what theories were used to predict their locations.

Answer 42

Neptune was predicted from the basic laws of physics(laws of gravity and motion). Uranus was discovered using the Titius-Bode Law

Question 43

What is unique about Uranus’s rotation, what caused this and how does this affect its seasons?

Answer 43

Its thought that something like a large planetoid pushed Uranus on its side. Each pole gets 42 years of continuous sunshine followed by 42 years of darkness.

Question 44

What is the internal structure (and compositions of layers) of Uranus and Neptune?

Answer 44

Cores are rocky, probably heavy metals and silicates. Mantles are slushy mixes of water, methane, ammonia and some other ‘ices’. Atmosphere starts off near the liquid planet as mostly methane, ammonia and water vapour but give ways to outer atmospheres of hydrogen and helium.

Question 45

Why do Uranus and Neptune have less hydrogen and helium than Saturn and Jupiter?

Answer 45

They have lower escape velocities. Planets are too small to retain great quantities of the 2 lightest gases

Question 46

Do these planets have magnetic fields? What creates them?

Answer 46

They both have magnetic fields. For Uranus, it doesn’t come from the centre, the generator has to do with the rotational motion between the ammonia and water layers. For Neptune, generated by the dynamo effect acting in the conducting fluid mantle

Question 47

What in the atmosphere makes the planets appear blue-green?

Answer 47

The methane in the atmosphere is whats making the colour. Red wave lengths are absorbed by the methane resulting in reflected light that has a high proportion in the green/blue spectrum

Question 48

How/why do the belt-zone cloud pattern form on Uranus?

Answer 48

Combination of the temperature gradient plus rotation of the planet gives rise to a belt-zone cloud patterns

Question 49

Although Uranus and Neptune have similar atmospheres, Neptune is a bit hazy – why?

Answer 49

Haze is thought to be a rather high concentration of organic molecules, caused by the breakdown of methane by light

Question 50

Uranus’s main satellites include Oberon, Titania, Umbriel, Miranda and Ariel.

a. Some of these have evidence of being tectonically active – what is this evidence?
b. What is the heat source that would drive active tectonics?
c. What makes some of these satellites dark in colour?
d. These satellites have icy surfaces – how well does ice preserve evidence of geological events (e.g. collisions or tectonics)?

Answer 50

a. Oberon has a mountain that was raised 20 km, Titania had a phase in which internal melting flooded the surface with water and filled the early craters with ice and the network of faults that crosses its surface.
b. ???
c. Probably dirty ice and rocks
d. When an object is made primarily of ice, it can ‘heal’ itself of scars rather easily.

Question 51

Triton is a satellite of Neptune:

a. Why might Triton crash into Neptune?
b. Triton is very cold – what element is liquid on the planet and how does this affect surface features?
c. Why does Triton have an atmosphere?
d. What is a probable source of heat that drives activity on Triton?

Answer 51

a. it has a retrograde orbit.
b. the decay of radioactive elements inside the satellite, is enough to sustain the liquid state of the subsurface nitrogen “groundwater”
c. Density gives the satellites an escape velocity of 1.4 km/s and together with the intense cold is enough for Triton to retain a very tenuous atmosphere
d. Generated by tidal action from neptune?