Lesson 9

Question 1

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

Answer 1

Their rapid rotation flings the mass near the equator outward

Question 2

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

Answer 2

100 million

Question 3

Why is Jupiter denser than Saturn?

Answer 3

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

Question 4

Why is Saturn almost as big as Jupiter, despite its smaller mass?

Answer 4

Jupiter’s greater mass compresses it more, thus increasing its density.

Question 5

Why do the jovian planet interiors differ?

Answer 5

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.

Question 6

The belts and zones of Jupiter are

Answer 6

alternating bands of rising and falling air at different latitudes.

Question 7

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

Answer 7

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

Question 8

What causes synchronous rotation?

Answer 8

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.

Question 9

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

Answer 9

tidal heating

Question 10

Which moon has the most substantial atmosphere?

Answer 10

Titan

Question 11

Why does Titan have such a nitrogen-rich atmosphere?

Answer 11

The nitrogen comes from the breakup of ammonia (NH3) by solar radiation and subsequent thermal escape of the hydrogen.

Question 12

Why do astronomers believe Triton may have been a planet that was captured by Neptune?

Answer 12

It orbits Neptune in the opposite direction of Neptune’s rotation.

Question 13

Why are Saturn’s rings so thin?

Answer 13

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

Question 14

What is the Cassini division of Saturn’s rings?

Answer 14

a large gap, visible from Earth

Question 15

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

Answer 15

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

Question 16

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

Answer 16

both the Sun and their interiors, in roughly equal proportions

Question 17

Jupiter’s colors come in part from its three layers of clouds. Which of the following is not the primary constituent of one of Jupiter’s cloud layers?

Answer 17

clouds of sulphuric acid

Question 18

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

Answer 18

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

Question 19

Which of the following statements about the moons of the jovian planets is not true

Answer 19

Most of the moons are large enough to be spherical in shape, but a few have the more potato-like shapes of asteroids.

Question 20

Which moon has a thick atmosphere made mostly of nitrogen?

Answer 20

Titan

Question 21

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

Answer 21

Europa

Question 22

What would happen to Jupiter if we could somehow double its mass?

Answer 22

Its density would increase but its diameter would barely change.

Question 23

Which of the following best why we see horizontal “stripes” in photographs of Jupiter and Saturn?

Answer 23

The light stripes are regions of high clouds, and the dark stripes are regions where we can see down to deeper, darker clouds

Question 24

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

Answer 24

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