AS101 Chapter 11 Questions

True or False: Hydrogen exists as a gas, liquid, and solid within Jupiter.

True

True or False: Jupiter does not have seasons because it has no appreciable axis tilt.

True

True or False: Some of the moons of the jovian planets have significant atmospheres.

True

What is the most abundant gas in Titan's atmosphere?

nitrogen

Some jovian planets give off more energy than they receive because of

ongoing contraction or differentiation.

How many more times is the atmospheric pressure in Jupiter's core greater than the atmospheric pressure at Earth's surface?

100 million

What causes synchronous rotation?

A massive planet exerts a tidal force on a moon that causes the moon to align itself such that its tidal bulges always point toward and away from the planet.

Why do the jovian planet interiors differ?

Accretion took longer further from the Sun, so the more distant planets formed their cores later and captured less gas from the solar nebula than the closer jovian planets.

How do the jovian planet interiors differ?

All have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium.

Which of the following statements about the rings of the four jovian planets is not true?

All probably look much like they did when the solar system first formed.

Why are Saturn's rings so thin?

Any particle in the ring with an orbital tilt would collide with other ring particles, flattening its orbit.

Why does Jupiter have several distinct cloud layers?

Different layers represent clouds made of gases that condense at different temperatures

Which moon is considered likely to have a deep, subsurface ocean of liquid water?

Europa

thought to have a deep, subsurface ocean of liquid water

Europa

True or False:Uranus continues to generate internal heat through gravitational contraction

False

The largest moon in the solar system is

Ganymede

What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size?

Ice has a lower melting point than rock.

Why are there no impact craters on the surface of Io?

Io did have impact craters but they have all been buried in lava flows.

Why is Io more volcanically active than our moon?

Io has a different internal heat source.

How much energy does Jupiter emit compared with how much it receives from the Sun?

It emits twice as much.

Why is Neptune denser than Saturn?

It has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks.

How does Jupiter's core compare to Earth's?

It is about the same size but is 10 times more massive.

Which of the following statements about Titan is not true?

It is the coldest moon in the solar system.

Why do astronomers think Miranda has such an unusual surface?

It underwent an episode of tidal heating in the past.

Why is Jupiter denser than Saturn?

Its higher mass and gravity compresses its interior.

Which of the following best explains why many jovian moons have been more geologically active than the Moon or Mercury?

Jovian moons are made mostly of ice that can melt or deform at lower temperatures than can the rock and metal that make up the Moon and Mercury.

Where are you if: Whipped by winds gusting at 10,000 km/hr, rising and falling in convective currents, you are not having a good time. On the rare occasions when you can assess your surroundings, you notice a horizon that seems to go on "forever" (or, at least, much farther than the horizon on Earth), and no solid surface anywhere. You get a glimpse of several large moons. The Sun races through your sky,requiring only about 5 hours to rise nearly due east, cross the meridian at an altitude of about 55° in the north, and then set due west.

Jupiter's Great Red Spot

How does the strength of Jupiter's magnetic field compare to that of Earth's magnetic field?

Jupiter's magnetic field is about 20,000 times as strong as Earth's

Most volcanically active body in the solar system

Jupiter's moon Io

Why do Uranus and Neptune have blue methane clouds but Jupiter and Saturn do not?

Methane does not condense into ice in the warmer atmospheric temperatures of Jupiter and Saturn.

Why does Neptune appear blue and Jupiter red?

Methane in Neptune's atmosphere absorbs red light.

Which of the following planets cannot be seen with the naked eye?

Neptune

Which previously unknown planet's location was predicted from mathematical calculations of orbital motions?

Neptune

Describe the leading scenarios for the origin of the planetary rings. What makes us think that ring systems must be continually replenished?

One scenario for the origin of the rings is that a wandering moon strayed into the Roche zone and was torn apart. Another scenario is that the material near the planet was prevented from forming a moon in the first place because of the strong tidal forces. Random orbits of the particles would cause collisions between particles that cross orbits, and this has the effect of making the rings very thin. Frequent collisions between particles or between particles and their planet's upper atmosphere cause ring particles to disintegrate within a few million years. Therefore, since the ring particles are rapidly disappearing, they must be continually replenished. Otherwise it would be very unlikely that we would be so lucky to view rings around all of the jovian planets during this short time period that they have rings

Planetary rings are

Orbiting in the equatorial plane of their planet, composed of a large number of individual particles that orbit their planet in accord with Kepler's third law, known to exist for all the jovian planets, and nearer to their planet than any of the planet's large moons.

Where are you if: 1. very cold 2. air pressure is tolerable 3. oceans of liquid methan 4. solar day is 16 earth days long

Saturn's moon: Titan

Which planet may have helium rain in its interior, and what does this rain do?

Saturn, where it generates heat as it falls downward.

Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why?

Temperatures on Jupiter and Saturn are too high for methane to condense.

Why does it make sense that the jovian planets farther from the Sun have less mass?

The differences in the sizes of the jovian planets are due to their capturing different amounts of gas from the solar nebula, since their cores are all about the same size. Icy planetesimals took longer to accrete in the outer solar system, because they were more spread out there. Thus, more distant jovian planets didn't have as much time as Jupiter to capture gas from the solar nebula before the nebula was cleared by the solar wind

Why is Jupiter denser than Saturn?

The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn.

The satellite Amalthea orbits Jupiter at just about the same distance in kilometers at which Mimas orbits Saturn. Yet Mimas takes almost twice as long to orbit. What can you deduce from this difference qualitatively? Since Jupiter and Saturn are not very different in radius, what else can you conclude?

The gravitational attraction of Saturn on Mimas is less than that of Jupiter on Amalthea; therefore, Saturn's mass must be less than Jupiter's. If Saturn is less massive but almost as large as Jupiter, its density must be lower.

Why does Titan have such a nitrogen-rich atmosphere?

The nitrogen comes from the breakup of ammonia (NH 3) by solar radiation and subsequent thermal escape of the hydrogen.

Why is the radiation so intense in the region that traces Io's orbit around Jupiter (the Io torus)?

The region is full of gases that become ionized after they are released from volcanoes on Io.

Why is there no large temperature variation from the poles to the equator on Jupiter?

The surface temperature on Jupiter is determined more by internal heat (from gravitational contraction) than by solar radiation. Thus the poles and the equator are at nearly the same temperature.

Why do jovian planets bulge around the equator, that is, have a "squashed" appearance?

Their rapid rotation flings the mass near the equator outward.

Jupiter and the other jovian planets are sometimes called "gas giants." In what sense is this term misleading?

They actually contain relatively little material in a gaseous state.

The target of the Huygens probe, which landed on its surface in 2005

Titan

Which moon has a thick atmosphere made mostly of nitrogen?

Titan

Which moon has the most substantial atmosphere?

Titan

Which moon shows evidence of rainfall and erosion by some liquid substance?

Titan

Which large jovian moon is thought to have been captured into its present orbit?

Triton

probably a captured moon

Triton

Suppose the jovian planet atmospheres were composed 100 percent of hydrogen and helium rather than 98 percent of hydrogen and helium. How would the atmospheres be different in terms of color and weather?

Without ingredients besides hydrogen and helium, the jovian planets would all be gray in color, and there would be no clouds or precipitation.

How thick are Saturn's rings from top to bottom?

a few tens of meters

What is the Cassini division of Saturn's rings?

a large gap, visible from Earth

The four Galilean moons around Jupiter are

a mixture of rock and ice.

The fact that most moons always show the same face to their planet is

a natural consequence of tidal forces acting on the moons.

The belts and zones of Jupiter are

alternating bands of rising and falling air at different latitudes.

The energy in the atmospheres of most of the jovian planets comes

both the Sun and their interiors, in roughly equal proportions.

How do astronomers think Jupiter generates its internal heat?

by contracting, changing gravitational potential energy into thermal energy

How do astronomers think Saturn generates its internal heat?

by raining dense helium droplets from higher to lower altitudes, resembling the process of differentiation

Which of the following best describes the internal layering of Jupiter, from the center outward?

core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer

The Huygens probe took numerous pictures as it descended to Titan's surface in 2005. What did the pictures show?

features or erosion, including what appeared to be dry river valleys and lakebeds

The main ingredients of most satellites of the jovian planets are

hydrogen compound ices

Which of the following is most unlikely to be found on Titan?

lakes of liquid water in the warmer equatorial regions

Which of the following does not yield information on jovian planet interiors?

spectroscopy of the cloud layers

Which of the following is not due to tidal forces?

the backward orbit of Triton (a moon of Neptune)

What mechanism is most responsible for generating the internal heat of Io that drives the volcanic activity?

tidal heating

True or False: If Jupiter were 10 times more massive, it would actually have a smaller radius.

true