Chapter 20 - Section 4 - The Outer Planets

Question 2

What are gas giants?

Answer 2

Jupiter, Saturn, Uranus and Neptune

Question 3

Why are they called gas giants?

Answer 3

Because Jupiter, Saturn and Neptune are so large

Question 4

What are gas giants made of?

Answer 4

mainly hydrogen and helium

Question 5

What keeps the gases from escaping the gas giants?

Answer 5

Because they are so big, they have very strong gravity that keeps gases in.

Question 6

All the gas giants have ______________________.

Answer 6

moons

Question 7

All gas giants are surrounded by ______________.

Answer 7

rings

Question 8

What is a ring?

Answer 8

a thin disk of small particles of ice and rock

Question 9

What is unusual about the rotation of Venus?

Answer 9

it rotates east to west – opposite of most other planets and moons

Question 10

What is the largest planet?

Answer 10

Jupiter

Question 11

Jupiter’s atmosphere is made up of

Answer 11

hydrogen and helium

Question 12

What is the “Great Red Spot”

Answer 12

a spot on Jupiter’s atmosphere that is a storm larger than earth.

Question 13

Name Jupiter’s four largest moons

Answer 13

lo, Europa, Ganymede and Cllisto

Question 14

The second largest planet.

Answer 14

Saturn

Question 15

Saturns largest moon

Answer 15

Titan

Question 16

Why is Uranus colder than Saturn?

Answer 16

It’s twice as far from the sun.

Question 17

Why does Uranus look blue-green?

Answer 17

methane in its atmosphere

Question 18

Uranus’s axis of rotation is tilted an an angle of about _______________

Answer 18

90 degrees

Question 19

Who discovered Uranus?

Answer 19

William Herschel

Question 20

Uranus’s moon have ________________ on their surfaces.

Answer 20

lava flows

Question 21

Uranus has at least ______________ moons.

Answer 21

25

Question 22

Neptune is ______________ (closer or farther) from the sun than Uranus.

Answer 22

farther

Question 23

Scientists think that Neptune is slowly _________.

Answer 23

shrinking

Question 24

The existence of Neptune was inferred from _____.

Answer 24

The orbit of Uranus. Uranus’s was not following the orbit predicted. Scientists believed that an unseen planet was affecting Uranus’s orbit.

Question 25

Neptune has at least _____ moons.

Answer 25

13

Question 26

Neptune’s largest moon

Answer 26

Triton

Question 27

How is Pluto different from the gas giants?

Answer 27

has a solid surface and it much smaller and denser than the other outer planets

Question 28

Pluto has ______ known moons.

Answer 28

3

Question 29

Pluto’s largest moon

Answer 29

Charon

Question 30

Pluto’s orbit is very ___________.

Answer 30

elliptical

Question 31

What is a dwarf planet?

Answer 31

Like a planet they are round and orbit the sun. However, a dwarf planet has not “cleared out the neighborhood” around its orbit.

Question 32

What is classified as a dwarf planet?

Answer 32

Pluto and two other bodies

Question 33

How long does it take Pluto to revolve around the sun?

Answer 33

248 years

Question 34

Why do all the gas giants have thick atmospheres?

Answer 34

Because they are so big they have stronger gravity. The gravity keeps the gasses from escaping.

Question 35

Why do some astronomers think that Pluto should not be classified as a planet?

Answer 35

A body even larger and farther from the sun than Pluto was discovered.