Chapter Menu

1
Chapter Menu
Chapter Introduction Lesson 1 Our Solar
System Lesson 2 Life in the Solar
System Lesson 3 Human Space Travel Chapter
Wrap-Up
NASA
2
Chapter Introduction

• How and where do scientists look for life in the
  solar system?

3
Chapter Introduction

• What do you think?

Before you begin, decide if you agree or disagree
with each of these statements. As you view this
presentation, see if you change your mind about
any of the statements.
4
Chapter Introduction
Do you agree or disagree?

• 1. Our solar system has eight planets.
• 2. Earths atmosphere is mostly oxygen.
• 3. Earths atmosphere protects life on Earth from
  dangerous solar radiation.
• 4. Scientists think conditions for life might
  exist on some moons in the solar system.

5
Chapter Introduction
Do you agree or disagree?

• 5. Astronauts float in space because there is no
  gravity above Earths atmosphere.
• 6. The United States is the only country with a
  human space-flight program.

6
Lesson 1 Reading Guide - KC
Our Solar System

• How do objects in the solar system move?
• How did distance from the Sun affect the makeup
  of objects in the solar system?
• What objects are in the solar system?

7
Lesson 1 Reading Guide - Vocab
Our Solar System

• astronomical unit
• planet
• dwarf planet
• satellite

• meteoroid
• meteor
• meteorite

8
Lesson 1-1
Origin and Structure of Our Solar System

• Five billion years ago, our solar system formed
  from a spinning cloud of hydrogen gas and dust.
• When gravity caused the cloud to collapse, the
  cloud began to spin faster and grow hotter.

9
Lesson 1-1
Origin and Structure of Our Solar System (cont.)

• When the center of the cloud became hot enough
  for nuclear reactions to occur, a star formedthe
  Sun.
• Small pieces of ice and rock orbiting the Sun
  clumped together and formed planets, asteroids,
  and other objects.

10
Lesson 1-1

• Scientists use astronomical units to measure
  distances in our solar system. An astronomical
  unit (AU) is Earths average distance from the
  Sun, nearly 150 million km.

11
Lesson 1-1
Origin and Structure of Our Solar System (cont.)

• The inner solar systemcontaining Mercury, Venus,
  Earth, and Marsextends to about 4 AU from the
  Sun.
• It also contains the asteroid belt between Mars
  and Jupiter, 24 AU from the Sun.

12
Lesson 1-1
Origin and Structure of Our Solar System (cont.)

• The outer solar system contains the planets
  Jupiter, Saturn, Uranus, and Neptune.
• The solar system is often divided into regions
  depending on distance from the Sun.

13
Lesson 1-1
Origin and Structure of Our Solar System (cont.)

• The outer solar system extends from Jupiters
  orbit to the Oort clouda large, spherical shell
  of icy planetesimals that scientists think orbits
  the Sun from about 5,000 AU to as far as 50,000
  AU away.

14
Lesson 1-1
Origin and Structure of Our Solar System (cont.)

• The solar system is made mostly of hydrogen gas.
• Ices, rocks, and metals make up less than 2
  percent of our solar systems mass.

15
Lesson 1-2

• The Suns gravity pulls on planets and other
  objects that revolve around it.
• The Sun and six of the eight planets, including
  Earth, rotate in a counterclockwise direction.

16
Lesson 1-2
Movement in the Solar System (cont.)

• Venus and Uranus rotate clockwise.
• While Earth rotates from west to east, objects in
  the sky appear to move from east to west.

17
Lesson 1-3
Movement in the Solar System (cont.)
Why do most objects in our solar system move in
the same direction?
18
Lesson 1-3
Objects in Our Solar System

• Scientists group objects in our solar system into
  categories based on makeup, size, distance from
  the Sun, and whether the object orbits the Sun or
  another object.
• As regions beyond the Sun cooled, some of the
  gases solidified into ices, rocks, and metals.

19
Lesson 1-3
Objects in Our Solar System (cont.)
How did the distance from the Sun affect the
makeup of objects in the solar system?
20
Lesson 1-3
Objects in Our Solar System (cont.)

• The Sun is made mostly of hydrogen gas.
• The Sun is the only star in our solar system, and
  it the largest object in the solar system.
• The Suns diameter is 10 times that of Jupiter
  and more than 100 times that of Earth.

21
Lesson 1-3
Objects in Our Solar System (cont.)

• A planet orbits the Sun, is large enough to be
  nearly spherical in shape, and has no other large
  objects in its orbital path.

22
Lesson 1-3
Objects in Our Solar System (cont.)

• The four inner planets formed from rocks and
  metal, are smaller than the outer planets, have
  few or no moons, and rotate slowly.

23
Lesson 1-3
Objects in Our Solar System (cont.)

• The four outer planets formed mostly from gas and
  ice, are large, have many moons, rotate quickly,
  and have rings.

24
Lesson 1-3
25
Lesson 1-3
26
Lesson 1-3
27
Lesson 1-4
Objects in Our Solar System (cont.)

• Dwarf planets orbit the Sun and are nearly
  spherical in shape, but they share their orbital
  paths with other objects of similar size.
• There are at least five dwarf planets in our
  solar system, but scientists think the solar
  system might contain hundredsmost of them
  orbiting the Sun beyond Neptune.

28
Lesson 1-4
Objects in Our Solar System (cont.)

• All known dwarf planets, including Pluto, are
  smaller than Earths moon.
• Ceres orbits the Sun between the orbits of Mars
  and Jupiter, in the asteroid belt.

29
Lesson 1-4
Objects in Our Solar System (cont.)

• Asteroids are small, rocky or metallic objects
  that are remnants from the solar systems
  formation.

NASA/JPL/USGS
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Lesson 1-4
Objects in Our Solar System (cont.)

• A satellite is an object that orbits a larger
  object other than a star.
• Natural satellites are also known as moons.
• There are over 170 moons in the solar system.

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Lesson 1-4
Objects in Our Solar System (cont.)

• Like the asteroid belt, the Kuiper belt contains
  remnants from the solar systems formation.
• Kuiper belt objects are mostly ice.

32
Lesson 1-4
Objects in Our Solar System (cont.)

• Comets are small objects made mostly of ice
  which revolve around the Sun with long,
  stretched-out orbits.

NASA
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Lesson 1-4

• Kuiper belt objects orbit the Sun beyond Neptune.
  Some comets originate in the Kuiper belt. Others
  originate farther away.

NASA
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Lesson 1-4
Objects in Our Solar System (cont.)

• A meteoroid is a solar system object that is
  smaller than an asteroid or a comet.
• A meteor is the streak of light created when a
  meteoroid enters Earths atmosphere.
• A meteorite is a meteoroid that strikes Earth.

35
Lesson 1-4
Objects in Our Solar System (cont.)
meteor from Greek meteoros, means high up
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Lesson 1-4
Objects in Our Solar System (cont.)
What objects are in our solar system?
37
Lesson 1 - VS

• The inner solar system extends from the Sun
  through the asteroid belt.

38
Lesson 1 - VS

• Even some asteroids have satellites.

NASA/JPL/USGS
39
Lesson 1 - VS

• Comet tails can be millions of kilometers long.

40
Lesson 1 LR1
What orbits the Sun, is large enough to be nearly
spherical, and has no other large objects in its
orbital path?
A. dwarf planet B. meteoroid C. planet D. satellit
e
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Lesson 1 LR2
The majority of objects in the Kuiper belt are
comprised of which type of matter?
A. gas B. ice C. metal D. rock
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Lesson 1 LR3
How is Pluto classified?
A. asteroid B. comet C. meteoroid D. dwarf
planet
43
Lesson 1 - Now
Do you agree or disagree?

• 1. Our solar system has eight planets.
• 2. Earths atmosphere is mostly oxygen.

44
Lesson 2 Reading Guide - KC
Life in the Solar System

• What conditions on Earth enable life to exist?
• What conditions on other bodies in the solar
  system might enable life to exist?
• Where might life possibly exist beyond Earth?

45
Lesson 2 Reading Guide - Vocab
Life in the Solar System

• astrobiology
• organic
• geyser

46
Lesson 2-1
Conditions for Life on Earth

• Despite the extreme conditions in which some
  organisms live, all of Earths life-forms need
  the same basic things to survive a source of
  energy, liquid water, and nourishment.
• Astrobiology is the study of the origin,
  development, distribution, and future of life in
  the universe.

47
Lesson 2-1
Conditions for Life on Earth (cont.)
astrobiology from Greek astron, means star
Greek bios, means life and Greek logia, means
study of
48
Lesson 2-1
Conditions for Life on Earth (cont.)
What do organisms on Earth need to survive?
49
Lesson 2-1
Conditions for Life on Earth (cont.)

• The Sun is the source of almost all energy on
  Earth.
• Sunlight provides light and thermal energy.
• A small percentage of organisms on Earth receive
  energy from chemicals or from Earth itself.

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Lesson 2-1
Conditions for Life on Earth (cont.)

• Earths atmosphere absorbs sunlight during the
  day and keeps thermal energy from escaping into
  space at night.
• Earths atmosphere absorbs most of the Suns
  ultraviolet light, as well as X-rays and other
  potentially harmful light from the Sun.
• Earths atmosphere also protects Earths surface
  from meteoroids.

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Lesson 2-1
Conditions for Life on Earth (cont.)

• Liquid water is necessary for all life on
  Earth.
• Depending on temperature and pressure on
  Earth, water is solid, liquid, or gas.

Royalty-Free/CORBIS
52
Lesson 2-1

• Water changes from a liquid to a gas or to a
  solid as its temperature and pressure change.

53
Lesson 2-1
Conditions for Life on Earth (cont.)
What would happen to water on Earths surface if
Earth had no atmosphere?
54
Lesson 2-1
Conditions for Life on Earth (cont.)

• Living things are nourished by nutrients they
  take from the air, water, and land around them.
• All molecules that provide nourishment for life
  on Earth contain carbon.
• Organic refers to a class of chemical compounds
  in living organisms that are based on carbon.

55
Lesson 2-1
Conditions for Life on Earth (cont.)
organic Science Use relating to carbon compounds
in living organisms Common Use relating to food
grown without fertilizers, pesticides, or
antibiotics
56
Lesson 2-1
Conditions for Life on Earth (cont.)

• Though it is possible that inorganic life could
  exist elsewhere, astrobiologists are most
  interested in places beyond Earth where water is
  liquid and carbon is plentiful.

57
Lesson 2-2
Looking for Life Elsewhere

• Because liquid water is essential for life on
  Earth, scientists look for places in our solar
  system, on the Moon, and beyond where liquid
  water might exist or might have existed in the
  past.
• Other than Earth, Mars is the planet scientists
  think is most likely to have liquid water.

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Lesson 2-2
Looking for Life Elsewhere (cont.)

• There is abundant evidence for water vapor and
  water ice on the Martian surface, and photographs
  show surface features on Mars that appear to have
  been carved by moving water.

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Lesson 2-2
Looking for Life Elsewhere (cont.)
Why do scientists think liquid water once might
have existed on Mars?
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Lesson 2-2
Looking for Life Elsewhere (cont.)

• Several moons in the outer solar system, such as
  Jupiters moon Europa, have surface features that
  indicate the presence of liquid water not far
  below.

Galileo Project/JPL/NASA
NASA/JPL/University of Arizona/University of
Colorado
61
Lesson 2-2
Looking for Life Elsewhere (cont.)

• Several other moons in the outer solar system,
  including Enceladus, a moon of Saturn, and
  Triton, a moon of Neptune, show evidence of
  geysers.
• A geyser is a warm spring that sometimes ejects a
  jet of liquid water or water vapor into the air.

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Lesson 2-2
Looking for Life Elsewhere (cont.)
Where might life exist in the solar system beyond
Earth?
63
Lesson 2 - VS

• Mostbut not alllife on Earth receives energy
  from the Sun.
• Features on Mars that look like streambeds might
  be evidence that liquid water once existed on
  the surface.
• Oceans of liquid water might be below the
  surface of some moons in the outer solar system.

Galileo Project/JPL/NASA
64
Lesson 2 LR1
In addition to a source of energy and
nourishment, what do all of Earths life-forms
need to survive?
A. ice B. oxygen C. liquid water D. water vapor
65
Lesson 2 LR2
Which term describes a class of chemical
compounds in living organisms that are based on
carbon?
A. astrobiology B. geyser C. meteoroid D. organic
66
Lesson 2 LR3
Other than Earth, what planet do scientists think
is most likely to have liquid water?
A. Jupiter B. Mars C. Saturn D. Venus
67
Lesson 2 - Now
Do you agree or disagree?
3. Earths atmosphere protects life on Earth from
dangerous solar radiation. 4. Scientists think
conditions for life might exist on some moons in
the solar system.
68
Lesson 3 Reading Guide - KC
Human Space Travel

• What technology has allowed humans to explore and
  travel into space?
• What factors must humans consider when traveling
  into space?

69
Lesson 3 Reading Guide - Vocab
Human Space Travel

• artificial satellite
• rocket
• space probe

70
Lesson 3-1
Technology and Early Space Travel

• An artificial satellite is any human-made object
  placed in orbit around a body in space.
• Hundreds of artificial satellites, such as
  communication satellites, operate in orbit
  around Earth.

U.S. Department of Defense
71
Lesson 3-1
Technology and Early Space Travel (cont.)

• A rocket is a vehicle propelled by the exhaust
  made from burning fuel.
• Rockets allow artificial satellites to escape
  Earths gravity.

72
Lesson 3-1
Robotic Space Probes

• A space probe is an uncrewed vehicle that travels
  to and obtains information about objects in
  space.
• Probes are equipped with cameras and scientific
  instruments that transmit data back to Earth.

Digital Vision/Getty Images
73
Lesson 3-1
Robotic Space Probes (cont.)

• It costs less and is safer to send probes rather
  than people into space.
• Another reason to send probes rather than people
  into space is that objects in space are very far
  away.

74
Lesson 3-1
Robotic Space Probes (cont.)

• The National Aeronautics and Space Administration
  (NASA) is the U.S. government agency responsible
  for most space missions and space-flight
  technology.
• Astronauts from more than 30 countries have
  traveled to space, and several countries have
  sent robotic missions to the Moon and beyond.

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Lesson 3-1
Robotic Space Probes (cont.)
astronaut from Greek astron, means star and
Greek nautes, means sailor
76
Lesson 3-1
Robotic Space Probes (cont.)
How do space probes help scientists explore space?
77
Lesson 3-3
Challenges for Humans in Space

• When astronauts travel into space, they must
  bring their environments and life-support systems
  with them.
• Astronauts must rely on their spacecraft and
  spacesuits to shield them from dangerous solar
  radiation and solar particles.

NASA
78
Lesson 3-3
Challenges for Humans in Space (cont.)

• Air circulation systems inside spacecraft supply
  oxygen and keep carbon dioxide, which people
  breathe out, from accumulating.
• Environmental control systems in spacecraft
  protect astronauts from temperature and pressure
  extremes.

79
Lesson 3-3
Challenges for Humans in Space (cont.)

• Astronauts in orbit around Earth are subjected to
  almost the same gravity as they are on Earths
  surface.
• As their spacecraft orbits Earth, the astronauts
  inside are continually falling toward Earth, but
  because their spacecraft is moving, they float
  instead of fall.

80
Lesson 3-3
Challenges for Humans in Space (cont.)
What factors must humans consider when traveling
into space?
81
Lesson 3-3
Challenges for Humans in Space (cont.)

• The space environment that astronauts experience
  is called microgravity.
• Microgravity exerts a smaller force on the
  astronauts bodies than the force of gravity they
  would experience on Earth.

82
Lesson 3-3
Challenges for Humans in Space (cont.)

• Living in microgravity, astronauts do not have to
  work as hard as they would on Earth to move
  around.
• Astronauts in space must exercise each day to
  keep their bodies strong for their return to
  Earth.

83
Lesson 3-4
Living and Working in Space

• The International Space Station (ISS) is a large,
  artificial satellite that orbits Earth.

84
Lesson 3-4
Living and Working in Space (cont.)

• The ISS crew conducts scientific and medical
  experiments.
• In the future, in addition to being an orbiting
  research laboratory, the ISS might serve as a
  testing and repair station for missions to the
  Moon and beyond.

85
Lesson 3-4
Living and Working in Space (cont.)

• Space transportation systems are the rockets, the
  shuttles, and other spacecraft that deliver cargo
  and humans to space.
• The space shuttle was NASAs first reusable
  transportation system.

Stocktrek/age fotostock
86
Lesson 3-4

• NASA is designing a new space transportation
  vehicle called Orion, with a goal of sending
  astronauts to the Moon and eventually to Mars.

87
Lesson 3 - VS

• When wearing an EMU suit, an astronaut can spend
  up to eight hours outside a spacecraft.
• Sleeping can be a challenge for astronauts in
  space.
• The space shuttle was NASAs first reusable
  transportation system.

Stocktrek/age fotostock
88
Lesson 3 LR1
Which U.S. government agency is responsible for
most space missions and technology?
A. EMU B. ISS C. NASA D. Orion
89
Lesson 3 LR2
Which is an uncrewed vehicle that travels to and
obtains information about objects in space?
A. rocket B. satellite C. space probe D. space
shuttle
90
Lesson 3 LR3
Air circulation systems inside spacecraft supply
oxygen and keep what from accumulating?
A. carbon dioxide B. gravity C. nitrogen
D. oxygen
91
Lesson 3 - Now
Do you agree or disagree?
5. Astronauts float in space because there is no
gravity above Earths atmosphere. 6. The United
States is the only country with a human
space-flight program.
92
Chapter Review Menu
Key Concept Summary Interactive Concept
Map Chapter Review Standardized Test Practice
93
The BIG Idea

• Scientists use space probes, artificial
  satellites, and human transportation systems to
  explore our solar system and look for evidence of
  life on Mars and some moons.

94
Key Concepts 1
Lesson 1 Our Solar System

• Our solar system formed from a spinning cloud of
  gas and dust. Most of the planets and other solar
  system objects orbit the Sun in the same
  direction the original cloud rotated.
• The Sun is made mostly of hydrogen gas. Objects
  close to the Sun are made mostly of rock and
  metals. Objects farther away are made mostly of
  ices and gases.
• The solar system includes the Sun, planets, dwarf
  planets, comets, natural satellites, asteroids,
  and meteoroids.

95
Key Concepts 2
Lesson 2 Life in the Solar System

• Life on Earth requires a source of energy, liquid
  water, and nourishment.
• Scientists search for places in the solar system
  where liquid water and organic carbon might
  exist.
• Scientists think life could possibly exist on
  Mars and/or some satellites of the outer planets.

96
Key Concepts 3
Lesson 3 Human Space Travel

• Humans have developed rockets, space probes,
  artificial satellites, and human transportation
  systems to help them explore and travel into
  space.
• When traveling, working, and living in space,
  humans must be protected from radiation,
  temperature and pressure extremes, and
  meteoroids. They must provide their own oxygen,
  and they must be prepared for a microgravity
  environment.

97
Chapter Review MC1
Which refers to objects that orbit the Sun and
are nearly spherical in shape but share their
orbital paths with other objects?
A. satellites B. meteoroids C. dwarf
planets D. comets
98
Chapter Review MC2
Which terms describes the streak of light created
when a meteoroid enters Earths atmosphere?
A. comet B. meteor C. meteorite D. satellite
99
Chapter Review MC3
Astrobiology is the study of the origin,
development, distribution, and future of which of
these?
A. carbon B. life in the universe C. stars D. wat
er
100
Chapter Review MC4
What is the source of almost all energy on Earth?
A. carbon B. oxygen C. the Sun D. water
101
Chapter Review MC5
Which describes any human-made object placed in
orbit around a body in space?
A. artificial satellite B. rocket C. space
probe D. space shuttle
102
Chapter Review STP1
What makes up most of the solar system?
A. hydrogen B. ice C. metals D. rocks
103
Chapter Review STP2
Which term refers to an object that orbits a
larger object other than a star?
A. comet B. dwarf planet C. planet D. satellite
104
Chapter Review STP3
What is necessary for all life on Earth?
A. carbon B. liquid water C. solid
water D. sunlight
105
Chapter Review STP4
Which vehicle is propelled by the exhaust made
from burning fuel?
A. artificial satellite B. rocket C. satellite D.
space probe
106
Chapter Review STP5
Which describes NASAs first reusable
transportation system?
A. International Space Station B. Orion C. space
probe D. space shuttle