Chapter 7

Question 1

What is comparative planetology?

Answer 1

The study of planets, moons, asteroids, and comets by comparing their similarities and differences.

Question 2

What is the first step in understanding our solar system?

Answer 2

Visualizing what it looks like as a whole.

Question 3

What is the Sun mostly composed of?

Answer 3

Hydrogen and Helium

Question 4

What percentage of the solar system’s total mass does the Sun contain?

Answer 4

More than 99.8%

Question 5

What are sunspots?

Answer 5

Spots on the Sun’s surface that appear dark because they are slightly cooler than their surroundings.

Question 6

Where does the Sun’s energy come from?

Answer 6

Nuclear fusion in its core.

Question 7

What is the solar wind?

Answer 7

Charged particles flowing outward from the Sun.

Question 8

What is the average distance of Mercury from the Sun?

Answer 8

0.39 AU

Question 9

Describe Mercury’s surface.

Answer 9

Desolate, cratered, with no active volcanoes, wind, rain or life

Question 10

Why does Mercury have extreme temperature variations?

Answer 10

Tidal forces from the sun have forced Mercury into an unusual rotation.

Question 11

What is unique about Venus’s rotation?

Answer 11

It rotates very slowly and in the opposite direction of Earth.

Question 12

What is the average surface temperature of Venus?

Answer 12

740 K (470°C or 880°F)

Question 13

What causes Venus’s extreme temperatures?

Answer 13

An extreme greenhouse effect.

Question 14

What is unique about Earth compared to other planets in our solar system?

Answer 14

It is the only known oasis of life.

Question 15

What percentage of Earth’s surface is covered by oceans?

Answer 15

Nearly three-fourths.

Question 16

What is the leading hypothesis for the Moon’s formation?

Answer 16

A giant impact early in Earth’s history.

Question 17

What is the average distance of Mars from the Sun?

Answer 17

1.52 AU

Question 18

What are the names of Mars’ two moons?

Answer 18

Phobos and Deimos

Question 19

What evidence suggests that Mars had liquid water in the past?

Answer 19

Dried-up riverbeds, rock-strewn floodplains, and minerals that form in water

Question 20

What is the average distance of Jupiter from the Sun?

Answer 20

5.20 AU

Question 21

What is the Great Red Spot on Jupiter?

Answer 21

A long-lived storm.

Question 22

What are the Galilean moons of Jupiter?

Answer 22

Io, Europa, Ganymede, and Callisto

Question 23

Which of Jupiter’s moons is the most volcanically active in the solar system?

Answer 23

Io

Question 24

What is the average distance of Saturn from the Sun?

Answer 24

9.54 AU

Question 25

What are Saturn's rings made of?

Answer 25

Countless small particles of rock and ice.

Question 26

What spacecraft has been observing Saturn since 2004?

Answer 26

The Cassini spacecraft

Question 27

Which of Saturn's moons has ice fountains spraying out from its southern hemisphere?

Answer 27

Enceladus

Question 28

Which moon in the solar system has a thick atmosphere?

Answer 28

Titan, a moon of Saturn.

Question 29

What is the average surface temperature of Earth?

Answer 29

290 K

Question 30

What are the two distinct groups that the planets fall into?

Answer 30

Inner planets and Outer planets