Chapter 11

In the far future, a daring interplanetary tourist wants to go "hang-gliding" on the jovian planet with the highest equatorial wind speeds. Which planet would have the fastest wind at its equator?

Neptune

The jovian planet that has the longest year (period of revolution) is:

Neptune

The first spacecraft to explore the environment of the planet Jupiter was called

Pioneer

The planet that orbits "on its side" (i.e. has its rotation axis perpendicular to the plane of its orbit) is:

Uranus

Much of what we have learned about the jovian planets and their satellites has come from the work of two spacecraft called:

Voyager

The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn's magnetism is:

hydrogen

What are the advantages of a robotic craft over a manned mission?

A robotic spacecraft does not have to be returned to Earth

The first spacecraft which did not merely fly by a jovian (or giant) planet, but actually went into orbit around it for an extended period of time was

Galileo

Approximately how long does it take Jupiter to complete one rotation?

10 hours

Approximately how long does it take for Jupiter to undergo one complete rotation?

10 hours

Approximately how long does it take for Jupiter to complete one orbital revolution around the Sun?

11 years and 10 months

Jupiter has enough mass to make 318 Earths. In contrast, Uranus and Neptune have only enough mass to make

15 Earths

There is a distinctly shaped geometric pattern (a polygon shape) in gas flow over the South Pole, while the North Pole seems to exhibit a predominantly circular flow.

False

Voyager 2 achieved its closest approach to Jupiter (and the Red Spot) on

July 9, 1979

The largest planet in the solar system (by mass) is

Jupiter

The planet that has an axis that points roughly straight up, and thus has no seasons to speak of, is:

Jupiter

Which of the jovian planets has the shortest period of rotation (the shortest day)?

Jupiter

Astronomers believe that Jupiter's strong magnetic field is caused by

a huge layer of metallic hydrogen inside Jupiter

At their centers, all the jovian planets have cores made of:

a solid mixture of rocky and icy materials under great pressure

Which of the following does the composition of a planet like Jupiter resemble: a. the Sun b. the Moon c. the Earth d. Mars e. the asteroids

a. the Sun

What do the magnetic fields of Jupiter, Uranus, and Neptune have in common?

all three have their magnetic axes offset from the center of the planet

Which of the following is NOT a correct statement about the ways the jovian planets differ from the terrestrial planets? a. the jovians are larger b. all the jovians have satellites around them and none of the terrestrials do c. the jovians are made mostly of liquid and gas d. the jovians are typically colder and further from the Sun e. the jovians have rings while the terrestrials do not

b. all the jovians have satellites around them and none of the terrestrials do

Which of the following spacecraft is NOT leaving the solar system? a. Pioneer 10 b. Pioneer 11 c. Galileo d. Voyager 1 e. Voyager 2

c. Galileo

Which of the following characteristics distinguishes Uranus from every other planet in our solar system? a. it has more than one moon b. its atmosphere is made of gases c. it rotates on an axis tilted almost 90 degrees to the circle of its orbit d. its orbit is significantly tilted relative to the orbits of the other planets e. its magnetic axis does not lie in the same direction as its rotation axis

c. it rotates on an axis tilted almost 90 degrees to the circle of its orbit

Which of the following statements about the seasons on Jupiter is correct? a. Jupiter has seasons pretty much like the Earth; its axis has the same tilt, and each season is about the same length b. Jupiter has the same axis tilt as the Earth, but each season on Jupiter is much longer c. Jupiter's axis is tilted much more than the Earth's so its seasons are much more intense d. Jupiter's axis is hardly tilted so it has no real seasonal variations e. Jupiter's orbit brings it much closer to the Sun in summer and much farther from the Sun in winter

d. Jupiter's axis is hardly tilted so it has no real seasonal variations

Which of the following statements about Jupiter's magnetosphere is TRUE? a. its source is a zone directly above the planet's cloudtops b. the magnetic field is 20 to 30 times weaker than the Earth's c. it is tilted so that it is almost perpendicular (at 90 degrees) to the equator of Jupiter d. it completely covers the inner satellites of Jupiter and is one of the largest structures in the solar system e. it is easily visible to the human eye with a small telescope

d. it completely covers the inner satellites of Jupiter and is one of the largest structures in the solar system

Which of the following statements about the Galileo probe that dropped into Jupiter is FALSE? a. it was the first spacecraft to enter the atmosphere of a jovian planet b. it sent back information for a little less than an hour c. it was slowed by atmospheric friction and a parachute d. it detected a lot of water and water vapor clouds on its way down e. it found that the temperature and pressure increased as it got further down

d. it detected a lot of water and water vapor clouds on its way down

The Red Spot of Jupiter is: a. variable in size b. a high pressure storm system in the atmosphere c. made of a reddish colored material (but we don't know what gives it the reddish color) d. long-lived (observed since the 1600's) e. all of the above

e. all of the above

Which of the following is NOT a way that Jupiter differs from terrestrial planets? a. its average density is lower b. it is farther away from the Sun c. it includes much more gas and liquid d. it is larger in diameter e. its surface has many more craters from early collisions

e. its surface has many more craters from early collisions

The dwarf planet Pluto was discovered in 1930. Since that time, which jovian planet has completed a full revolution around the Sun? a. Jupiter b. Saturn c. Uranus d. Neptune e. more than one of the above

e. more than one of the above

The primary clouds in the atmospheres of Jupiter and Saturn are composed of:

frozen ammonia crystals

The synchrotron radiation (radio waves) that astronomers first observed from Jupiter in the 1950's comes from:

high speed electrons spiraling around the planet's strong magnetic field

By far the most abundant element in the giant (jovian) planets is:

hydrogen

The big problem with the Galileo spacecraft is that

its main antenna is stuck in the closed position

One way to measure how long Jupiter takes to rotate is to watch the giant storms in its atmosphere go around. A more fundamental way to measure the rotation is to:

measure the changes in the planet's radio waves, which are controlled by its magnetic field

The bluish color that makes the atmosphere of Neptune so beautiful to the human eye is caused by the interaction of sunlight with what gas?

methane

The upper clouds in the atmosphere of Neptune are composed of:

methane

To obtain the wonderful images of the jovian planets in our textbook (out where the sunlight is a lot fainter) what did the Voyager spacecraft cameras have to do as they flew by each world?

swivel the cameras backwards to keep pointing in the same direction as the craft flew by

What was a surprise to astronomers when they carefully examined Neptune with the Hubble Space Telescope in 1994?

the Great Dark Spot had disappeared

What allowed the Voyager 2 spacecraft to make a "tour" of all four of the jovian planets in the late 1970's and the 1980's?

the four planets were approximately aligned on one side of the Sun and we used the gravity of each planet to speed up the spacecraft to get to the next one in its path

One reason that we have such a complex system of belts/zones/storms in Jupiter's atmosphere is that:

the planet rotates very rapidly

The same process that explains why astronomers see less helium in the upper atmosphere of Saturn when they take spectra also explains

the reason Saturn is warmer than we expect

At the moment when the Voyager spacecraft got closest to Uranus, the Sun was shining directly on the planet's south pole. Uranus takes about 17 hours to rotate once on its axis. If Voyager took a photo of the south pole 8.5 hours later, what would it observe?

the south pole was brightly lit, with the Sun shining down on it