6th - Science Chaper 21 Outline

Question 1

The _____________ in the solar system orbit the Sun.

Answer 1

Planets

Question 2

The Sun and the objects that orbit it make up the ______________.

Answer 2

Solar system

Question 3

The largest object in the solar system is the ____________.

Answer 3

Sun

Question 4

The Sun is a star made up mostly of ____________ gas.

Answer 4

Hydrogen

Question 5

_____________ produces enormous amounts of energy in the Sun.

Answer 5

Nuclear fusion

Question 6

Objects orbit the Sun because it applies ________ forces on them.

Answer 6

Gravitational

Question 7

Objects that orbit the Sun include planets, dwarf planets, asteroids, and _____________. These objects ___________ the Sun’s light.

Answer 7

Comets, reflect

Question 8

A planet has nearly ________ shape.

Answer 8

Spherical

Question 9

There are _____ planets in the solar system.

Answer 9

8

Question 10

The four planets closer to the Sun are called the ______________ planets.

Answer 10

Inner

Question 11

Inner planets are made mainly from __________ material.

Answer 11

Rocky

Question 12

The four planets farthest from the Sun are called the __________ planets.

Answer 12

Outer

Question 13

Outer planets are made mostly of ice and ______.

Answer 13

Gases

Question 14

Because the outer planets are much larger than the inner planets, they are sometimes called __________.

Answer 14

Gas giants

Question 15

A(n) ____________ is a spherical object that orbits the Sun, is not the moon of another planet, and has less mass than any of the eight planets.

Answer 15

Dwarf planets

Question 16

Millions of small, rocky objects called ___________ orbit the Sun in a bel between Mars and Jupiter.

Answer 16

Asteroids

Question 17

A(n) _______________ orbits the Sun in an oval-shaped orbit and is made of dust, gas, and ice.

Answer 17

Comets

Question 18

The __________ is used to measure long distances in the solar system.

Answer 18

Astronomical unit

Question 19

One astronomical unit (AU) is the average distance from Earth to the _________.

Answer 19

Sun

Question 20

One way an object in the solar system moves is by orbiting, or _____________ around another planet.

Answer 20

Revolve

Question 21

The amount of time it takes an object to revolve once around the Sun is its ____________.

Answer 21

Period of revolution

Question 22

Objects in the solar system also spin, or _________.

Answer 22

Rotate

Question 23

The time it takes an object to rotate once is its ___________.

Answer 23

Period of rotation

Question 24

The shape of a planet’s orbit is a(n) __________, which is a stretched-out circle.

Answer 24

Ellipse

Question 25

The Sun is at one of the __________ of the ellipse, so the distance between a planet and the Sun changes as the planet moves.

Answer 25

Foci

Question 26

A planet moves __________ when it is closer to the Sun than when it is farther away.

Answer 26

Faster

Question 27

The mass of a planet is much _________ than the mass of nearby objects.

Answer 27

Larger

Question 28

The inner planets are those closet to the _________. They are also called the ___________.

Answer 28

Sun, terrestrial planets

Question 29

The inner planets are made of ___________ and metallic materials.

Answer 29

Rock

Question 30

The outer layers of the inner planets are in the ___________ state.

Answer 30

Solid

Question 31

_____________ is the planet closet to the Sun.

Answer 31

Mercury

Question 32

Mercury has no gases close to its surface, which means it has no ___________.

Answer 32

Atmosphere

Question 33

Because of its small mass, Mercury's ___________ is not strong enough to hold gases to its surface.

Answer 33

Gravity

Question 34

Because Mercury has no wind to move energy from place to place, the temperatures on the side of Mercury facing the Sun are always extremely _______________.

Answer 34

High

Question 35

Mercury's surface is covered with impact ___________, smooth plains, and high cliffs.

Answer 35

Craters

Question 36

Mercury has a core made of ___________ and nickel. It's mantle is made of oxygen and _________.

Answer 36

Iron, silicon

Question 37

__________ is the second planet from the Sun.

Answer 37

Venus

Question 38

Venus ___________ more slowly than it revolves, so a day on Venus is longer than a year on Earth.

Answer 38

Spins/rotates

Question 39

Unlike most other planets, Venus rotates from ________ to __________.

Answer 39

East, west

Question 40

Most of Venus's atmosphere is made up of ______________.

Answer 40

Carbon dioxide

Question 41

Venus is covered by a thick layer of ____________.

Answer 41

Clouds

Question 42

The clouds on Venus are made of ___________.

Answer 42

Acid

Question 43

Venus is the ____________ planet in the solar system.

Answer 43

Hottest

Question 44

The high temperatures on Venus are caused by the ___________.

Answer 44

Greenhouse effect

Question 45

The greenhouse effect increases surface temperature because the ____________ traps solar energy.

Answer 45

Atmosphere

Question 46

Most of the surface of Venus is covered by solidified __________.

Answer 46

Lava

Question 47

The third planet from the Sun is _________.

Answer 47

Earth

Question 48

Earth's atmosphere is made up of ___________ and a mixture of gases.

Answer 48

Water vapor

Question 49

The atmosphere produces a(n) ____________ that increases Earth's average surface temperature.

Answer 49

Greenhouse effect

Question 50

_________________ is supported on Earth because of its atmosphere, large bodies of liquid water, and moderate temperature range.

Answer 50

A variety of life

Question 51

Earth has a solid inner core and a(n) ________ outer core.

Answer 51

Liquid

Question 52

The __________ surrounds the outer core.

Answer 52

Mantle

Question 53

Earth's crust is broken into large sliding _________.

Answer 53

Plates

Question 54

Earth's _________ is made mostly of oxygen and silicon.

Answer 54

Crust

Question 55

Mars is the ________ planet from the Sun.

Answer 55

Fourth

Question 56

Mars has _____ small moons.

Answer 56

2

Question 57

Many probes have examined the surface of Mars; most have looked for signs of __________.

Answer 57

Water

Question 58

Mars's atmosphere contains mostly _____________.

Answer 58

Carbon dioxide

Question 59

Mars's surface appears to be red because it's soil contains ______________.

Answer 59

Iron oxide

Question 60

Ice caps on Mars are made up of ice and frozen _____________.

Answer 60

Carbon dioxide

Question 61

Features on Mars's surface include craters, lava flows, canyons, and the largest known ____________ in the solar system.

Answer 61

Mountain

Question 62

The outer planets are made of materials that are usually ___________ on Earth.

Answer 62

Gases

Question 63

Gravitational forces produced by the sizes of these planets change gases into __________.

Answer 63

Liquids

Question 64

___________ is the largest planet in the solar system.

Answer 64

Jupiter

Question 65

Although it takes 12 years to revolve around the Sun, Jupiter _________ faster than any other planet.

Answer 65

Spins

Question 66

Jupiter has a system of _________ around it.

Answer 66

Rings

Question 67

Jupiter's atmosphere contains helium but it mostly made up of ____________.

Answer 67

Hydrogen

Question 68

Jupiter's rotation stretches its clouds into colorful _______________.

Answer 68

Swirling bands

Question 69

The ______________ on Jupiter is a storm that has lasted more than 300 years.

Answer 69

Great Red Spot

Question 70

Jupiter's entire structure is made up of 80 percent hydrogen, about 20 percent ___________, and small amounts of other materials.

Answer 70

Helium

Question 71

Jupiter has a solid core that is surrounded by __________.

Answer 71

Thick liquid layer

Question 72

The four largest moon's of Jupiter are called _____________. These are lo, _________, Ganymede, and Callisto.

Answer 72

Galilean Moons, Europa

Question 73

Like Jupiter, Saturn rotates __________ and has clouds in bands.

Answer 73

Rapidly

Question 74

Saturn is mostly made of ____________ and helium.

Answer 74

Hydrogen

Question 75

Saturn has the largest ___________ system in the solar system.

Answer 75

Rings

Question 76

Saturn has _________ bands of rings, each of which contains thousands of smaller rings.

Answer 76

Seven

Question 77

The rings are made mainly of ______ particles.

Answer 77

Ice

Question 78

Most of Saturn's moons are small, but one of them, __________, is larger than the planet Mercury.

Answer 78

Titan

Question 79

Uranus's atmosphere contains mostly hydrogen and helium, with small amounts of ____________.

Answer 79

Methane

Question 80

Beneath Uranus's atmosphere is a slushy layer of water, ________, and other materials.

Answer 80

Ammonia

Question 81

Uranus might have a rocky ___________.

Answer 81

Solid core

Question 82

The rotational axis of Uranus is ________ more than that of other planets.

Answer 82

Tilted

Question 83

Uranus has at least ______ moons and a small ring system.

Answer 83

27

Question 84

The atmosphere and interior of Neptune are similar to ____________.

Answer 84

Uranus

Question 85

Neptune has at least _______ moons and a faint ring system.

Answer 85

13

Question 86

A dwarf planet is a sphere that orbits a(n) __________.

Answer 86

Star

Question 87

A dwarf planet has objects similar in _______ orbiting near it or crossing its orbital path.

Answer 87

Mass

Question 88

The dwarf planets in the solar system are _______, Ceres, Eris, Makemake, and Haumea.

Answer 88

Pluto

Question 89

Ceres is located in the __________ belt. It is the __________ dwarf planet in the solar system.

Answer 89

Asteroid, smallest

Question 90

Pluto has a rocky core surrounded by _____. It has _________ known moons.

Answer 90

Ice, 3

Question 91

________ is the largest dwarf planet. It is three times farther from the Sun than the dwarf planet _________ is.

Answer 91

Eris, Pluto

Question 92

Makemake and Haumea are dwarf planets in the _____________.

Answer 92

Kuiper belt

Question 93

Asteroids orbit the Sun in a band between _______ and Jupiter.

Answer 93

Mars

Question 94

The largest asteroid is called _________.

Answer 94

Pallas

Question 95

Asteroids are chunks of rock and ________.

Answer 95

Ice

Question 96

Comets are made up of rocks, ice, and _______.

Answer 96

Dust

Question 97

_________________ between the particles in a comet hold it together.

Answer 97

The gravitational attraction

Question 98

Comets ________ the Sun in long elliptical orbits.

Answer 98

Orbit

Question 99

As a comet approaches the Sun, a bright _______ can develop on the comet.

Answer 99

Tail (coma)

Question 100

The ____________ is the solid, inner part of a comet.

Answer 100

Nucleus

Question 101

As the comet approaches the Sun, it heats, changing some ice in the nucleus into a(n) __________.

Answer 101

Bright tail

Question 102

Energy from the Sun pushes gas and dust particles away from the nucleus and makes it _________.

Answer 102

Glow

Question 103

___________ comets take less than 200 years to orbit the Sun. They usually come from the ______________.

Answer 103

Short-period, Kuiper belt

Question 104

___________ comets take more than 200 years to orbit the Sun. They come from the ____________.

Answer 104

Long-period, Oort Cloud

Question 105

A small, rocky particle that moves through space is a(n) ___________.

Answer 105

Meteoroid

Question 106

As it passes through Earth's atmosphere, friction with the air makes a meteoroid and the air around it _________.

Answer 106

Hot

Question 107

A streak of light in the atmosphere mad by a glowing meteoroid is a(n) ____________.

Answer 107

Meteor

Question 108

Most meteoroids _________ up in the atmosphere.

Answer 108

Burn

Question 109

A meteoroid that strikes the surface of a planet or a moon is called a(n) __________.

Answer 109

Meteorite

Question 110

A meteorite can form a bowl-shaped depression called a(n) ____________ in the surface it strikes.

Answer 110

Impact crater