Download Erosion - Delta Education

Delta
Science
Reader
Erosion
Delta Science Readers are nonfiction student
books that provide science background and
support the experiences of hands-on activities.
Every Delta Science Reader has three main
sections: Think About . . . , People in Science,
and Did You Know?
Be sure to preview the reader Overview Chart
on page 13, the reader itself, and the teaching
suggestions on the following pages. This
information will help you determine how to
plan your schedule for reader selections and
activity sessions.
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Reading for information is a key literacy skill.
Use the following ideas as appropriate for your
teaching style and the needs of your students.
The After Reading section includes an assessment
and writing links.
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VERVIEW
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In the Delta Science Reader Erosion,
students read about Earth’s structure. They
find out about the slowly moving plates that
make up Earth’s surface and how they are
related to mountain building, trenches,
earthquakes, and volcanoes. They learn
about physical and chemical weathering and
how they contribute to soil formation. They
are introduced to the causes of erosion and
deposition and the landforms that are the
results of these forces. They also read about
soil conservationists and the ways they work
to conserve soil and control erosion. Finally,
students learn about floods.
Students will
learn the layers and composition of Earth
discover that landforms are the result of a
combination of constructive and
destructive forces
explore the ways erosion, weathering, and
deposition change Earth’s surface features
examine nonfiction text elements such as
table of contents, headings, and glossary
interpret photographs and graphics to
answer questions
complete a KWL chart
Delta Science Reader—Erosion
461
• Identify causes and effects of forces related
to plate movements, earthquakes,
weathering, and erosion
• Draw conclusions about weathering and
erosion
• Identify main ideas and supporting details
in text passages
• Compare and contrast physical and
chemical weathering
• Demonstrate critical thinking
• Interpret graphic devices
• Summarize text information
• Explain the steps in the process of cave
formation
NONFICTION TEXT ELEMENTS
Erosion includes a table of contents, headings,
photographs, captions, diagrams, boldfaced
terms, and a glossary.
The following terms are introduced in context
and defined in the glossary: arch, barrier
island, chemical weathering, continental
glacier, convection, core, crust, delta,
deposition, dune, earthquake, erosion, fertile,
flood, floodplain, glacial till, glacier, gravity,
groundwater, humus, landforms, mantle, mass
movement, mineral, moraine, oxbow lake,
physical weathering, plates, rock, runoff,
sandbar, sea-floor spreading, sediment,
sinkhole, soil, soil horizon, soil profile, stack,
subduction, valley glacier, volcanic island,
volcano, weathering.
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Read the title aloud, and invite students to
share what they know about the topic from
their personal experiences and hands-on
explorations in science. To stimulate
discussion, ask questions such as these:
What happens to things that are left
outside, unprotected from the weather? How
do you think wind, rain, ice, and snow
affect things in nature, such as rocks? What
kinds of changes might weather cause in
Earth’s surface features?
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Begin a group KWL chart by recording facts
students know about erosion in the K column.
You may want students to copy the KWL chart
so they can maintain their own charts as they
read.
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CONTENT VOCABULARY
cover? (a rock formation; a rocky or desert
landscape; a rock or cliff with a hole carved in
it) How do you think this rock shape was
formed? (Accept all ideas.) You may wish to
explain that the photograph shows a natural
rock formation in Arches National Park in
Utah. The rock shape is one of more than
1,500 sandstone arches and “windows” in the
park. As students read the book, they will find
out how forces of nature worked to create
such formations.
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What
I Know
What
I Want
to Know
What
I Learned
What
I Want to
Explore
Further
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BEFORE READING
Build Background
Access students’ prior knowledge of erosion
by displaying and discussing the cover. Ask,
What do you see in the photograph on the
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Preview the Book
Explain that when students preview
nonfiction, they should look at the title, the
table of contents, headings, boldfaced words,
photographs, illustrations, charts, graphics,
and captions.
Then preview the book with students. Call
attention to the various nonfiction text
elements and explain how they can help
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READING IN THE
CONTENT AREA SKILLS
questions on the KWL chart to set an overall
purpose for reading.
students understand and organize what they
read. Ask questions such as these: How do
the headings help you predict what you will
read about? What do you see in this
picture? How do you think it will help you
understand the text? Explain that the words
in boldface type are important words related
to erosion. Point out that these words are
defined in the glossary. Choose one word and
have students find its definition in the
glossary.
GUIDE THE READING
Preview the book yourself to determine the
amount of guidance you will need to give for
each section. Depending on your schedule
and the needs of your class, you may wish to
consider the following options:
• Whole Group Reading Read the book
aloud with a group or the whole class.
Encourage students to ask questions and
make comments. Pause as necessary to
clarify and assess understanding.
Conclude the preview by inviting students to
suggest questions they would like to have
answered as they read the book. Tell them to
add the questions to the W column of the
KWL chart.
Preview the Vocabulary
You may wish to preview some of the
vocabulary words before reading, rather than
waiting to introduce them in the context of
the book. Possibilities include creating a word
wall, vocabulary cards, sentence strips, or a
concept web.
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© Delta Education. Photocopying and distribution prohibited.
earthquake
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• Independent Reading Some students may
be ready to read independently. Have them
rejoin the class for discussion of the book.
Check understanding by asking students to
explain in their own words what they have
read.
Tips for Reading
glacier
• If you spread out the reading over several
days, begin each session by reviewing the
previous day’s reading and previewing
what will be read in the upcoming session.
forces of
change
erosion
weathering
flood
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For example, many words are related to
forces that affect Earth’s surface features, or
landforms. Develop a web like the one that
follows.
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• Shared Reading Have students work in
pairs or small groups to read the book
together. Ask students to pause after each
text section. Clarify as needed and discuss
any questions that arise or have been
answered.
volcano
Concept web for forces of change.
Set a Purpose
Discuss with students what they might expect
to find out from the book, based on their
preview. Encourage them to use the
• Begin each text section by reading or
having a volunteer read aloud the heading.
Have students examine any illustrations or
graphics and read accompanying captions
and labels. Discuss what students expect
to learn, based on the heading,
illustrations, and captions.
• Help students locate context clues to the
meanings of words in boldface type.
Remind them that these words are defined
in the glossary. Provide help with words
that may be difficult to pronounce.
Delta Science Reader—Erosion
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gap? (No, hot magma pushes up between
the plates and forms new crust.) What is
this process called? (sea-floor spreading)
What two effects can happen when one
plate bumps or crashes into another?
(One plate can slide up over the other,
forming a mountain range and a deep
ocean trench. The two plates can be
forced together, pushing up blocks of
crust and forming a mountain range.)
What is the process called when one
plate sinks under another plate?
(subduction) Point out the prefix sub- and
ask students what they think it means.
(under) Can they think of other words with
the prefix sub-? (submarine, subway,
suburb, subtotal, subtract)
• As appropriate, model reading strategies
students may find helpful for nonfiction:
adjust reading rate, ask questions,
paraphrase, reread, visualize.
Think About . . . (pages 2–13)
Pages 2, 3 What Is Earth’s Structure?
Layers, Moving Plates
• Check comprehension by asking, What are
Earth’s three main layers? (the crust, the
mantle, and the core) How many layers
does the core have? What are they? (two,
the outer core and the inner core) What
do you notice about the thickness of the
crust compared to the rest of Earth’s
layers? (The crust is very thin.) Then have
students read the section titled “Layers”
on page 2.
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• Then have students finish reading pages 2
and 3 and study the diagrams at the
bottom of page 3. Assess comprehension
by having students summarize the main
ideas about plates. (Earth’s surface is
made up of separate moving sections
called plates. Convection in the mantle
forms convection currents that make the
plates move. The slowly moving plates
cause changes in Earth’s surface,
especially at plate boundaries.)
• Ask, What happens when plates move
away from each other? Do they leave a
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• If necessary, provide help with the
pronunciation of Celsius (SEL-see-us)
and Fahrenheit (FAIR-uhn-hite).
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• Ask, What is the main idea—the most
important point—about the crust on
page 2? (The crust covers Earth’s entire
surface.) What details support this main
idea? (The crust is Earth’s rocky outer
layer; the continents and the oceans are
on the crust.)
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• Check comprehension by having students
explain what is happening in each of the
diagrams at the bottom of the page. How
did the diagrams help you understand
these processes? (They show in pictures
what the text describes in words.)
Further Facts
• The idea that the continents have changed
position—which led to the theory of plate
tectonics—was first proposed in 1912 by a
German scientist named Alfred Wegener
(1880–1930). He suggested that at one
time the existing continents were joined
together as one supercontinent, which he
called Pangaea, meaning “all lands.”
• Pangaea began to split up about 200
million years ago. The continents continue
to move. Europe and North America are
estimated to be moving apart about
2–4 cm (about 0.75—1.5 in.) a year.
Page 4 Earthquakes and Volcanoes
• Before students read page 4, invite them
to share what they know about
earthquakes and volcanoes. Then have
them read the section on earthquakes.
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• Generate interest in the text by asking,
What do you think is inside Earth?
Explain, Long ago, people had no way of
knowing what Earth was like inside.
Today, scientists have instruments that
have given us a good idea of Earth’s
insides. Have students view the diagram
of Earth’s inner structure on page 2 and
read the caption and labels.
After reading, discuss the causes and
effects of earthquakes. Ask, What can
happen when pressure bends or cracks a
plate? (It can cause an earthquake.) What
effect did an earthquake have on the
road in the photograph? (The earthquake
caused a wide, deep crack to form in the
road.) Where do some earthquakes
happen? (at boundaries where plates slide
past or push against each other)
• Next, have students read the section on
volcanoes. Point out that volcanoes both
destroy and create Earth’s landforms. Ask,
How do volcanoes destroy landforms?
(They can blow off the tops of mountains.)
How do volcanoes create landforms?
(Lava hardens and builds up land.
Volcanoes under the ocean can form
volcanic islands. The mid-ocean ridge is a
volcanic mountain chain. All new ocean
floor comes from volcanoes.)
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• There are about 1,500 historically active
volcanoes in the world. Some estimates of
the number of undersea volcanoes exceed
1 million.
• Most of Earth’s active land volcanoes
are in a circle around the Pacific Ocean.
Many earthquakes also take place here.
This area is called the Ring of Fire. The
reason there are so many volcanoes and
earthquakes in the Ring of Fire is that this
is where many of Earth’s plates meet the
Pacific Plate.
• Before having students read page 5, write
the term weathering on the board. Ask
students what they notice about the word.
(It has the word weather in it.) Explain that
weathering is the term used for a force
that can change rocks. Invite students
to speculate on what is involved in
weathering. (Accept reasonable responses.
Students should infer that weathering may
involve certain weather conditions.)
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• Have students read the introduction on
page 5. Ask, What is weathering? (the
breaking down of rocks into smaller
pieces) What natural forces are involved
in weathering? (wind, water, temperature
changes, plants) What are the two kinds
of weathering? (physical weathering and
chemical weathering)
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Further Facts
• Chains of volcanoes can form over hot
spots—very hot places deep in Earth’s
mantle—as a moving plate slides across
the hot spot. This is how the Hawaiian
Islands were formed. The islands at the
northwest end of the chain formed first.
Other islands formed as the Pacific Plate
continued moving northwest. A new
volcano growing on the ocean floor
southeast of the island of Hawaii (the Big
Island) may someday become another
island in the state. It is already named:
Loihi.
Page 5 What is Weathering? and Physical
Weathering
• Have students read page 5 to find out
about physical weathering. Assess
understanding by having students
summarize how each natural force causes
changes in rocks. (Running water tumbles
rocks around and breaks them up. Wind
blows sand against rocks and wears away
the rock. Temperature changes cause
water in rocks to freeze and break the
rocks apart. Plant roots can grow into
cracks and break rocks apart.)
Page 6 Chemical Weathering
• Have students examine the photographs
on page 6 and read the captions. Then
have them read the text to learn about
chemical weathering. After they read, have
them compare and contrast physical and
chemical weathering. Ask, How are
physical and chemical weathering alike?
(They both break down rocks.) How are
they different? (In physical weathering,
rocks are broken down by natural physical
processes and forces, such as water
freezing and melting in cracks, rocks being
tumbled by water, wind blowing sand
against rocks, and plants growing in
cracks. In chemical weathering, water,
Delta Science Reader—Erosion
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the movement of weathered rock and soil
by water, ice, and wind.) What conclusion
can you draw about how long it takes
for weathering and erosion to change
Earth’s surface? (The process takes a very
long time.)
oxygen, and acids change the chemical
makeup of rocks and break them down.)
• If necessary, provide help with the
pronunciation of oxygen (OK-sih-juhn),
carbon dioxide (KAR-buhn die-OK-side),
lichens (LIE-kenz), and acidic (uh-SID-ik).
Page 7 Soil Formation
• Have students read about soil formation
on page 7 and study the cutaway diagram
of a soil profile. Ask, What is soil mostly
composed of? (weathered rock) What else
does soil contain? (decayed plant and
animal material, called humus, and water
and air) To check comprehension, have
students summarize the three main layers
of soil and what each is made of. (topsoil,
made of sand, silt, clay, and humus;
subsoil, made of bits of rock mixed with a
little humus; parent layer, made of large
pieces of rock with no humus) Ask, What
is another name of layers of soil? (soil
horizons) Why do you think no plants or
animals live below the subsoil? (Students
may recognize that without humus, the
parent material lacks enough of the right
kind of nutrients to support life.)
• Contrast some of the very slow processes
of weathering, erosion, and deposition
with the rapid earth-changing events
students have read about: volcanoes and
earthquakes. As students read the next
sections about different forces of erosion,
tell them to think about whether the forces
work quickly or slowly to reshape the land.
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• If necessary, provide help with the
pronunciation of humus (HYOO-muhs).
Page 8 What Causes Erosion and
Deposition?
• Have students read page 8, study the
photographs, and read the captions to
learn about erosion and deposition.
Ask, What is the difference between
weathering and erosion? (Weathering is
the breaking down of rocks by wind,
water, and other natural forces. Erosion is
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• What are the results of weathering and
erosion? (The shape of the land is
changed. Some of Earth’s landforms are
created by weathering and erosion.)
Discuss the definition of landforms as
shapes or features of Earth’s surface.
Make a class list of landforms students
have seen or know about. Decide which
are the primarily caused by weathering
and erosion. (Students may suggest
valleys, canyons, gullies or ravines, stone
arches such as those shown on the cover,
mesas, sand dunes, cliffs, or caves.)
• Point out that landforms are the result
of a combination of constructive and
destructive forces. Ask, What do you
think the term destructive force means?
Give an example. (A destructive force is
one that breaks down material or is
harmful to the land, as when chemical
weathering wears away rock to create
a cave or when windblown sand carves
a rock formation like the one on the
cover.) What do you think the term
constructive force means? Give an
example. (A constructive force is one that
builds up or makes something new, or is
helpful for the land, as when a volcano
makes a new island or a mountain range
is built at a plate boundary.)
Page 9 Running Water
• Have students read the text about running
water on page 9. Ask, What is the main
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• Have students describe the steps in the
process by which chemical weathering
creates huge underground caves.
(Rainwater and carbon dioxide mix
together and create weakly acidic
groundwater. The acid dissolves parts of
rocks underground. The holes in the rocks
get larger and larger, forming caves.)
idea of this section? (Moving water is a
main cause of erosion.) What three main
things affect the amount of erosion a
stream or river causes? (how steep the
land is, the number and type of plants on
the land, the amount of water that is
moving) How do plants slow down
erosion? (Their roots hold the soil in place.)
What conclusion can you draw from this
about land that has been cleared for
farming or another purpose? (Students
may realize that cleared land is more
vulnerable to erosion than uncleared land.)
• Ask, What are some ways in which
erosion and deposition create
landforms? (Rivers wear away rock,
forming valleys and canyons. Winding
rivers can change course and form oxbow
lakes. Sediments dropped by rivers when
they enter the ocean settle to the bottom
and form new land called deltas.)
© Delta Education. Photocopying and distribution prohibited.
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• If necessary, provide help with the
pronunciation of deposition (deh-puh-ZIHshuhn).
Page 10 Waves
• Have students read the text about waves
on page 10 and look at the photographs
and captions. Ask, How do waves both
destroy and create landforms? (Waves
wear away rock, creating sea cliffs and
forming arches. Waves carry sand and
pebbles from one place to another. Sand
deposited by waves can form sandbars
and barrier islands. Stones deposited by
waves form rocky beaches.)
• Have students summarize the different
types of mass movement. (rockslides,
when gravity causes loose rocks to fall;
mudflows, or rivers of mud; slumping,
when soil and plants move together as a
mass; creep, which is very slow mass
movement)
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• Before students read the section on
groundwater, review with them what they
learned about chemical weathering on
page 6. Ask, What happens when water
in the ground mixes with carbon
dioxide? (It forms a weak acid that
dissolves rock and can hollow out
underground caves.) Ask whether any
students have ever toured a cave, and
invite them to share their observations.
Explain that students will learn more
about the effects of groundwater when
they read page 12. Then have them read
the paragraphs under “Groundwater.” Ask,
How does groundwater cause
deposition? (When groundwater becomes
less acidic, it deposits the rock that was
once dissolved in it.) What is the result of
this kind of deposition? (As the water
drips, it creates stalactites that hang down
from the ceiling of a cave and stalagmites
that build up on the floor.)
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• Have students read the text about gravity
and mass movement on page 11. Ask, What
is mass movement? (the movement of
large amounts of rock and soil downhill)
How is gravity related to mass
movement? (Gravity causes mass
movement.)
Pages 12, 13 Groundwater, Wind, and
Glaciers
• Students may be interested to know the
origins of the terms oxbow lake and delta.
Explain that both names are related to the
shape of the landform. An oxbow lake
resembles an oxbow—a U-shaped frame
attached to a yoke for a team of oxen; the
oxbow forms a collar for the ox’s neck. A
river delta is triangular in shape,
resembling the uppercase form of delta,
the fourth letter of the Greek alphabet: Δ.
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Page 11 Gravity and Mass Movement
• Invite students to speculate how wind
causes erosion and deposition. Students
may suggest that wind picks up sand and
dust in one place and drops it in another.
Have them read the section about wind on
pages 12 and 13 to confirm their ideas.
Then ask, How does wind cause erosion?
(It picks up and carries away dust and sand
Delta Science Reader—Erosion
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them about the drought and dust storms
of the 1930s, when wind picked up and
carried away the soil. Ask, What can slow
down soil erosion? How? (plants; their
roots hold soil in place)
and deposits them in another place. Wind
blasts rocks with the sand it carries and
grinds them down.) What is one type of
landform formed by wind? (sand dunes)
• Have students read the section on glaciers
on page 13. Ask, What is a glacier? (a
huge moving body of ice) What is the
difference between a valley glacier and a
continental glacier? (A valley glacier is like
a river of ice; a continental glacier is a
sheet of ice that covers large areas of
land.) How do glaciers change Earth’s
surface? (They wear away rocks and move
soil and rocks to new places.) You may
want to explain that there have been at
least six periods in Earth’s history when
much of Earth’s surface was covered with
ice. We call these periods ice ages.
• After students read, have them confirm
the inferences they made. Ask, What do
soil conservationists do? (They work to
prevent and control erosion of soil.) Have
students summarize some of the methods
soil conservationists have developed.
(strip cropping, or planting two different
crops side by side; leaving stubs of plants
in fields after crops are harvested;
planting windbreaks; grading stream
banks; and placing rocks and plants along
the banks)
About Floods
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• Have students read page 15 to learn about
floods. After they read, ask, Why do you
think most flooding in the United States
occurs in the spring? (That is when snow
that falls in the mountains during the
winter melts and flows into streams and
rivers.)
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• If necessary, provide help with the
pronunciation of stalactites (stuh-LAKtites), stalagmites (stuh-LAG-mites),
Antarctica (ant-ARK-tih-kuh), and moraine
(moh-RANE).
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People in Science (page 14)
Soil Conservationists
• Before students read, ask whether they
know what a conservationist is. (a person
who works to save endangered things) Ask,
What do you think a soil conservationist
does? (works to save soil) Have students
make inferences about the need for soil
conservation, based on what they have
read about erosion. If necessary, remind
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Did You Know? (page 15)
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• Point out that floods are another force
that is both destructive and constructive.
Ask, How do floods destroy? (They flood
houses, wash away roads and bridges,
drown crops, and harm or kill people and
wildlife.) How are floods helpful? (They
deposit new, fertile sediment on a river’s
floodplain.)
Further Facts
• Levees—embankments built along the
edges of a stream or river—are an ancient
method of flood control that is still being
used. The ancient Egyptians built a series
of levees along the Nile River for more
than 966 km (600 mi).
• One of the largest levee systems today is
the one built along the Mississippi River. It
was begun by French settlers in the early
eighteenth century. Today the system
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• You may wish to tell students that
because of the huge dust storms that
struck the central United States in the
1930s, the area was called the Dust Bowl.
The natural grasslands had been plowed
under in order to plant wheat. When the
drought killed the wheat, the exposed
topsoil was carried off by the wind.
Thousands of families were forced to
leave their homes. The problem was
eventually brought under control after
windbreaks were planted and some of the
native grassland was restored.
includes more than 11,200 km (7,000 mi)
of levees. Some levees reach 15 m (50 ft)
in height.
• Another method of flood control is the
construction of artificial channels. The Los
Angeles River, which runs through that
city’s downtown, is contained by a
concrete channel. While protecting the city
from flooding, the channel has taken away
the natural beauty of the river.
AFTER READING
Complete the KWL chart you began with
students before reading by asking them to
share the answers to their questions. Call on
volunteers to retell each text section. Then
have students use the information in the KWL
chart to write brief summary statements.
© Delta Education. Photocopying and distribution prohibited.
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Present the following as writing assignments.
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Writing Links/Critical Thinking
Discuss with students how using the KWL
strategy helped them understand and
appreciate the book. Encourage them to
share any other reading strategies that
helped them understand what they read.
Direct attention to the fourth column in the
chart and ask: What questions do you still
have about erosion? What would you like to
explore further? Record students’ responses.
Then ask, Where do you think you might be
able to find this information? (Students
might mention an encyclopedia, science
books, and the Internet.) Encourage students
to conduct further research.
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3. What are the six main causes of erosion
and deposition? (running water, waves,
gravity and mass movement, groundwater,
wind, glaciers)
4. What is mass movement, and what causes
it? (Mass movement is the movement of
large amounts of rock and soil downhill. It
is caused by gravity.)
Summarize
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2. What slow processes cause changes in
Earth’s surface, and how do they do this?
(Weathering breaks rocks down into
smaller pieces. Chemical weathering can
wear away rocks and create caves. In
erosion, water, ice, and wind move
weathered rock and soil from one place to
another.)
Review/Assess
Use the questions that follow as the basis for
a discussion of the book or for a written or
oral assessment.
1. What fast processes cause changes in
Earth’s surface, and how do they do this?
(Earthquakes shake the ground and can
cause landslides and cracks in Earth’s
surface. Volcanic eruptions can blow off the
tops of mountains; lava flows build up land.
Other fast processes include rockslides,
mudflows, floods, slumps, and wave action
during a major storm.)
1. You have learned that landforms are the
result of a combination of constructive and
destructive forces. Describe how these
forces affect Earth’s surface features.
(Students should mention that constructive
forces include volcanic eruptions, which
create new land and can form volcanic
islands, and deposition of sediment.
Destructive forces include weathering and
erosion, which break down rocks into
smaller pieces.)
2. The text states that the main cause of
erosion is running water. Think about the
various causes of erosion described. Why
do you think running water is a more
powerful force than waves, gravity,
groundwater, wind, and glaciers? (Students
may recognize that running water in the
form of rain, runoff, and streams occurs in
most places on Earth and affects surface
features. Waves affect only seashores,
gravity can work only on material that has
already been weathered, groundwater
affects only underground materials, wind is
not constant, and glaciers occur in only a
few places on Earth.)
Delta Science Reader—Erosion
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Science Journals: You may wish to have
students keep the writing activities related to
the Delta Science Reader in their science
journals.
References and Resources
For trade book suggestions and Internet sites,
see the References and Resources section of
this teacher’s guide.
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Delta
Science
Reader
Solar System
Delta Science Readers are nonfiction student
books that provide science background and
support the experiences of hands-on activities.
Every Delta Science Reader has three main
sections: Think About . . . , People in Science,
and Did You Know?
Be sure to preview the reader Overview Chart
on page 14, the reader itself, and the teaching
suggestions on the following pages. This
information will help you determine how to
plan your schedule for reader selections and
activity sessions.
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Reading for information is a key literacy skill.
Use the following ideas as appropriate for your
teaching style and the needs of your students.
The After Reading section includes an assessment
and writing links.
© Delta Education. Photocopying and distribution prohibited.
OVERVIEW
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In the Delta Science Reader Solar System,
students take a tour of the Sun and the
nine planets. Other space objects such as
comets, asteroids, and meteoroids are
explored. Students read about the rotation
and revolution of the planets and the causes
of night and day, seasonal changes, and the
phases of the Moon. The book describes the
work of a planetary geologist. In addition,
students discover how telescopes work.
Students will:
discover facts about the Solar System
explore the planets and other objects in the
Solar System
discuss the function of a table of contents,
headings, and a glossary
interpret photographs and graphics to
answer questions
complete a KWL chart
organize information in a variety of ways
Delta Science Reader—Solar System
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• Compare and contrast planets
• Determine the main idea of a paragraph
• Recognize cause-effect relationships
related to planetary conditions
• Draw conclusions about planetary facts
• Demonstrate critical thinking
• Interpret graphic devices
• Summarize
• Categorize planets
To stimulate discussion, ask questions
such as these: What are some of the
objects in our Solar System? How many
planets are there? What is Earth’s closest
neighbor in space?
Begin a class KWL chart by recording facts
students know about the Solar System and
its planets in the K column. You may wish
to copy the KWL chart and ask students to
maintain their own charts as they read.
K
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What
I Know
What
I Want
to Know
What
I Learned
NONFICTION TEXT ELEMENTS
Solar System includes a table of contents,
headings, photographs and illustrations,
captions, diagrams, boldfaced terms, a
biographical sketch, and a glossary.
The following terms are introduced in
context and defined in the glossary:
asteroid, astronomer, atmosphere, axis,
comet, crater, day, Earth, ellipse, gas giant,
gravity, inner planet, Jupiter, Mars, Mercury,
meteor, meteorite, meteoroid, moon, Moon,
Neptune, orbit, outer planet, phase, planet,
Pluto, revolution, revolve, rotate, satellite,
Saturn, solar, solar system, space probe,
star, Sun, telescope, Uranus, Venus, year.
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BEFORE READING
Build Background
Access students’ prior knowledge of the
Solar System and its planets by displaying
and discussing the cover. Ask, Do you
know what planet this is? (Saturn) What
do you think these other objects are?
(some of Saturn’s moons) Then read the
title aloud and invite students to share
what they know about the topic from their
personal experiences and prior hands-on
explorations in science.
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Preview the Book
Take a few minutes to have students look
through the book. Explain the steps
involved in previewing nonfiction: think
about the title, read the table of contents,
read the headings, read boldfaced words,
and examine any photographs,
illustrations, charts, and graphics.
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What
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Further
Call attention to the various nonfiction text
elements and explain how each feature can
help students understand what they read.
Point out that the table of contents lists all
the main headings in the book and their
page numbers. Ask, How do the headings
help you know what you will learn about?
Point to some of the photographs and ask
questions such as: What does this photo
show you? How do you think it will help
you understand the text? Explain that the
words in boldfaced type are important
words related to our Solar System that
students will learn when they read the
book. Point out that these words are
defined in the glossary. Choose one word
and have students find its definition in
the glossary.
© Delta Education. Photocopying and distribution prohibited.
READING IN THE
CONTENT AREA SKILLS
• Shared Reading Have students form
pairs or small groups and read the book
together. Ask students to pause after each
text section. Clarify the text as needed.
Discuss any questions that arise or have
been answered.
Following the preview, ask, What questions
do you have about our Solar System that
you would like this book to answer? Record
students’ responses in the W column of the
KWL chart. Explain that they will add to the
chart as they are reading and complete it
when they finish reading.
Preview the Vocabulary
You may wish to preview some of the
vocabulary words before reading, rather than
waiting to introduce them in the context of
the book. Possibilities include creating a word
wall, vocabulary cards, sentence strips, or a
concept web.
For example, have students categorize words.
List words from the glossary that can be
grouped in different ways, such as moon,
asteroid, revolve, comet, planet, and rotate.
After helping students define the words, ask,
Into what groups can we put these words?
What would be a good name for each
category? (Objects in Our Solar System—
asteroid, comet, moon, planet; Ways Planets
Move—revolve, rotate)
Set a Purpose
© Delta Education. Photocopying and distribution prohibited.
Discuss with students what they might expect
to find out when they read the book, based
on their preview. Encourage them to use the
questions on the KWL chart to set an overall
purpose for reading.
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UIDE THE READING
Preview the book yourself to determine the
amount of guidance you will need to give for
each section. Depending on your schedule
and the needs of your class, you may wish to
consider the following options:
• Whole Group Reading Read the book
aloud with a group or the whole class.
Encourage students to ask questions and
make comments. Pause as necessary to
clarify and assess understanding.
Tips for Reading
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• If you spread out the reading over several
days, begin each session by reviewing the
previous day’s reading and previewing
what will be read in the upcoming session.
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• Begin each text section by reading or
having a volunteer read aloud the heading.
Discuss what students expect to learn,
based on the heading. Have students
examine photographs, illustrations, and
graphics and read accompanying captions
and labels.
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• Independent Reading Some students may
be ready to read independently. Have them
rejoin the class for discussion of the book.
Check understanding by asking students to
explain in their own words what they read.
• Help students locate context clues to the
meanings of words in boldface type.
Remind them that these words are defined
in the glossary. Provide help with words
that may be difficult to pronounce.
• As appropriate, model reading strategies
students may find helpful for nonfiction:
adjust reading rate, ask questions,
paraphrase, reread, visualize.
Think About . . . (pages 2–13)
Pages 2–3 Our Solar System
• Direct students’ attention to the diagram of
the Solar System on page 2. Ask questions
to elicit facts about the Solar System. How
many planets are there? (nine) Which one
is closest to the Sun? (Mercury) Which is
the farthest? (Pluto) Where is Earth in the
Solar System? (third from the Sun) Which
is the biggest planet? (Jupiter) Which is
the smallest? (Pluto)
Delta Science Reader—Solar System
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• Generate interest in the text by asking,
As you sit here, are you moving or
staying still? Explain, Everyone on
Earth is moving—because the Earth
itself is moving! We’re being carried
along by the Earth as it turns on its
axis and as it travels around the Sun.
Have students read page 2 to find out
about our Solar System and the ways in
which the Earth moves.
Further Facts
• Check comprehension by asking,
What is our Solar System? (the Sun
and everything that moves around it)
What is the difference between
revolving and rotating? (Revolving is
moving in a path around something;
rotating is turning on an axis.)
Saturn Roman god of agriculture
and time
Mercury messenger of the ancient Roman
gods
Venus Roman goddess of love and beauty
Mars Roman god of war
Jupiter king of the Roman gods
Neptune Roman god of the sea
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• If necessary, provide help with the
pronunciation of Mercury (MER-kyuhree), Jupiter (JOO-puh-tur), Uranus
(YOOR-un-uhss), and ellipse (i-LIPS).
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the land of the dead
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Page 3 What Is the Sun Like?
• Before reading “What Is the Sun Like?”
have students study the photograph of
the Sun. Invite volunteers to describe
what they see. Have students read the
caption to find out about the Sun’s size
and some of its features. Ask, What is
shown coming off the Sun’s surface?
(cloud of matter erupting) You may wish
to share with students that these giant
eruptions of matter are called solar
prominences. Ask, What are the light
and dark areas shown on the Sun?
(The light areas are hotter places, and
the dark areas are cooler places.)
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• Before reading the first paragraph on
page 3, have students read the caption
at the top and study the diagram of
the Sun and the Earth. Discuss what
the diagram shows. Ask, When it
is summer in the northern part of
the world, what season is it in the
southern part of the world? (winter)
Read the paragraph below the diagram.
Ask, How does the diagram help
you understand the text? (It shows in
picture form what the words describe.)
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Uranus the sky personified as a god and
father of the Titans (a family of giants) in
Greek mythology
• Have students read the text about the
Sun on page 3. Ask, Why is the Sun so
important for life on Earth? (It provides
heat and light.) Point out that most
living things get their food energy from
green plants. Green plants use the
Sun’s energy to make this food.
• Check understanding by asking, What
is a star? (a huge ball of glowing gas
that produces light and heat)
As appropriate, tell students that the
Sun is an average star in terms of its
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Discuss with students the meaning of
the word system. (a group of objects
that work together as one unit) Discuss
that in a system, the parts usually have
an effect on one another. Ask, What
would happen if the Sun were
removed from the Solar System? (The
planets would fly off into space,
because there would not be enough
gravity to keep them in orbit.)
The planets were named after ancient
mythological characters:
but it is different from Earth in many
ways. What are some of the differences?
(Venus rotates in the opposite direction;
its day lasts 243 Earth days; it is covered
with clouds; it is much hotter.)
temperature and the material that it is
made of. In terms of its mass, the Sun is a
fairly large star. In fact, it is the central
and largest body in the Solar System.
Most of the mass (99.8 percent) in the
Solar System is in the Sun.
Venus is the easiest planet to see without
the aid of a telescope. It can be seen in
the direction of the Sun, near the horizon,
just before sunrise or just after sunset.
Because of this, we sometimes call Venus
the morning or evening star.
• Ask, What is the most surprising thing
you learned from reading this section?
(Responses will vary.)
Page 4 The Inner Planets: Mercury
• Have students read the introduction. Then
discuss the Mercury Facts feature with
them. You may wish to use the facts
provided to begin a nine-column Planetary
Facts table that contains information
about all nine planets. Explain, A table is
a good way to organize information. It
makes facts easy to read and compare.
• Have students read page 4 to find out
about Mercury. Ask, Why do you think
Mercury takes less time than any other
planet to revolve around the Sun? (It is
the planet closest to the Sun and has a
shorter distance to travel.) Why can’t
Mercury be seen at night? (Students may
infer that because Mercury is between
Earth and the Sun, the night side of Earth
faces away from it.) Why do you think
Mercury gets so hot during the day and
so cold at night? Explain that Mercury has
no atmosphere around it to trap heat, so it
gets very hot while the Sun is shining, but
loses its heat quickly when the Sun sets.
© Delta Education. Photocopying and distribution prohibited.
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• If necessary, provide help with the
pronunciation of atmosphere
(AT-muhss-fihr).
Page 5 Venus
• Discuss the Venus Facts with students and
add the facts to the table. Ask, What do
you notice about the length of a day
and a year on Venus? (A day lasts longer
than a year.)
• Have students read page 5. Then say,
Venus is sometimes called Earth’s twin,
Page 6 Earth
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• After discussing the Earth Facts with
students, add the facts to the table. Point
out that the year is 365 1/4 days long. Ask,
What happens to that extra quarter of a
day? If necessary, explain that we add a
day to our calendar every four years. We
call the year in which that takes place a
Leap Year.
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• If necessary, provide help with the
pronunciation of carbon dioxide
(KAR-buhn dye-OK-side).
• Read the first paragraph and ask, What
is the main idea—the most important
idea—expressed in this paragraph?
(Earth is the only planet that has the
atmosphere, water, and temperature that
most living things need.) What conclusion
can you draw from this? (Earth is the
only planet that people can live on.)
• Ask students to examine the diagram on
page 6, then read the text. Ask, What did
you learn by studying the diagram and
reading the text? (how day and night are
caused) What is the name for Earth’s
movement that causes day and night?
(rotation)
Page 7 Earth’s Moon
• Have students look at the photograph of
the Moon on page 7. Before reading the
text, invite students to share what they
know about the Moon. Remind students
that our knowledge of the Moon comes
not only from telescopes and space
Delta Science Reader—Solar System
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• Ask students to read the text on page 7
and examine the diagram of the Moon’s
phases. Guide them to see that when
the Moon is between the Earth and the
Sun, it is difficult to see because the
side facing us is dark. When the Moon
is to one side of the Sun, we see a
crescent or half moon. When the Moon
is exactly opposite the Earth and the
Sun, it is full. Ask, Did you find the
diagram helpful? Try explaining in
words what the diagram shows. Which
do you think is the better way of
presenting this information? Why?
(Students will probably say the diagram
is the better way because you can
quickly see what causes the changes;
an explanation in words takes longer.)
Page 8 Mars
• Discuss the Mars Facts with students
and add them to the table. Show
students how they can use the table to
compare and contrast the inner planets.
Say, Think about the facts about the
surfaces of the inner planets. What do
they all have in common? (rocky crust,
plains, high places, craters) What type
of landform is found on many of the
inner planets? (volcanoes)
Mars’s Olympus Mons is the largest
volcano in the Solar System. It is
24 kilometers (about 15 miles) high
and 600 kilometers (about 372 miles)
across.
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• Encourage students to use the diagram
of views of the Moon from Earth to
determine the meanings of waxing and
waning. Students should be able to see
that the lighted portion of the Moon’s
surface that we see increases in size
when the crescent is waxing and
decreases when it is waning. Explain
that gibbous means that more than half
but not all of the Moon’s disk is lighted.
• Ask, Why do you think so many
space probes have been sent to Mars?
Explain, if needed, that Mars used to
be much like Earth, and scientists have
been trying to find signs that it once had
life. Have students draw conclusions
about whether people could live on Mars
without special equipment. (No, because
the air doesn’t have much oxygen; it is
also very cold.)
• Point out that, like the Earth and the
Moon, most objects in the Solar System
move in regular and very predictable
ways. Because of this, we can predict the
length of each day and year, the phases
of the moon, and when events like solar
and lunar eclipses may happen.
• You may wish to tell students that the
names of Mars’s moons mean “fear”
(Phobos) and “panic” (Deimos). They
were named after the two sons of the
god Mars in Greek mythology.
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• If necessary, provide help with the
pronunciation of gibbous (GIB-us).
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• Read the text and caption on page 8.
Tell students that although there may
be no liquid water on the surface of
Mars now, scientists believe that the
planet once had rivers and oceans as
Earth does.
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• Direct students to look at the photograph
of Mars. Ask, Why do you think Mars is
called the “Red Planet”? (The rocks and
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broward county hands-on science
• If necessary, provide help with the
pronunciation of Sojourner (SOH-jerner), Phobos (FOH-buhss), and Deimos
(DEE-muhss).
© Delta Education. Photocopying and distribution prohibited.
probes; astronauts actually landed on
the Moon and brought back Moon
rocks. The Moon is the only planetary
body that people have visited. On July
20, 1969, Neil Armstrong and Buzz
Aldrin became the first people to walk
on the Moon. Six U.S. spacecrafts
(Apollos 11, 12, 14, 15, 16, and 17)
landed on the Moon between 1969 and
1972.
Page 9 The Outer Planets: Jupiter
common? (both have strong winds and
storms, both give off more heat than they
get from the Sun) What conclusion can
you draw from the fact that Jupiter and
Saturn give off more heat than they
receive from the Sun? (They produce their
own heat.)
• Read the introduction with students. You
may wish to tell students that not long
ago, Saturn was the only planet known to
have rings.
• Discuss the Jupiter Facts on page 9 and
add them to the table. Explain that almost
four hundred years ago a scientist named
Galileo used a telescope to observe the
night sky. In 1610, he saw Jupiter’s four
largest moons. The known number of
Jupiter’s moons increased as space probes
or improvements in telescopes provided
us with more information. In 2002,
astronomers found 11 new moons,
bringing the total to 39.
• Read the text on page 9. Ask students to
describe what Jupiter looks like in the
photograph. Ask, How is Jupiter’s
appearance different from that of the
inner planets? (It does not have craters,
mountains, and other landforms.) Explain
that scientists believe that Jupiter has a
liquid metal interior with a rocky core.
© Delta Education. Photocopying and distribution prohibited.
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• Read and discuss the Uranus Facts on
page 11 and add them to the table. Ask,
What do you notice about the length of
the planets’ years? (They keep getting
longer.) What is the cause of this? (Each
planet is farther away from the Sun and
has a longer distance to travel to go
around it.)
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• Read the text on page 11. Remind students
that they learned that almost all of the
planets have a tilted axis. Tell them that
Uranus’s axis is so tilted (97.9 degrees)
that the planet circles the Sun lying on its
side. Since it takes 84 years to complete
one orbit, Uranus’s polar regions each
have 42 years of darkness and 42 years of
light. Uranus, like Venus and Pluto, also
rotates “backward,” or clockwise, instead
of counterclockwise.
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Jupiter’s Great Red Spot is located in the
lower right of the photograph. The small
black spot in the lower left of the
photograph is actually the shadow of
Europa, one of Jupiter’s moons.
Page 11 Uranus
• Tell students that Jupiter’s four largest
moons are the size of small planets. In
fact, all are bigger than Pluto and the
largest, Ganymede, is bigger than Mercury.
Ask, Why isn’t Ganymede called a planet?
(It revolves around Jupiter, not the Sun.)
Page 10 Saturn
• Have students look at the photograph of
Saturn on page 10. Read the Saturn Facts
and add them to the table. Ask, How are
Jupiter and Saturn alike? (huge size,
made of gas, lots of moons, length of day)
• Read the text on page 10. Then say, Before
you read the text, you named some ways
in which Jupiter and Saturn are alike.
What else do these planets have in
• Inform students that until Voyager 2
flew past Uranus in 1986, only five of its
moons were known. Ask, Why do you
think Uranus’s other moons were not
discovered before then? (Students may
speculate that the moons are too small
and faint to be seen through a telescope.)
Uranus’s moons are named after
characters from the plays of Shakespeare
and a famous poem by Alexander Pope.
Other moons in our Solar System are
named after characters from Greek
mythology.
• Students may be interested to know that
Uranus was almost named Herschel after
the astronomer (William Herschel) who
discovered it. However, some astronomers
felt that the planet should have a name
from classical mythology like the rest.
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• Read and record the Neptune Facts.
Then read the text about Neptune. Ask,
What other planets did Voyager 2
visit? (Jupiter, Saturn, Uranus)
• Guide students to compare and
contrast the gas giant planets. Ask,
Which of the other gas giant planets
is most similar to Neptune? (Uranus)
How are they alike? (size, length of
day, color, made of similar gases, ring
system) In what ways are Uranus and
Neptune different? (number of moons,
length of year, Uranus gives off little
heat and rotates in a different direction)
• Read the Pluto Facts with students and
record them in the table. Ask, How is
Pluto different from the other outer
planets? (small size, rocky, only one
moon) Which planets does Pluto
resemble more? (Mercury, Venus,
Earth, Mars)
Page 13 Other Objects in Our
Solar System
• Before reading page 13, ask what other
objects in the Solar System students
know about. Encourage them to share
their ideas.
• Tell students to read the text on page 13
and look at the photograph of Halley’s
comet. You may wish to share with
students that comets have been called
“dirty snowballs.” Ask, What makes
that a good description of a comet?
(Comets are made of dust and ice mixed
together.) What causes a comet’s long,
glowing tail? (The Sun’s heat starts to
vaporize the comet, forming its tail. The
Sun’s light reflects off the tail.)
• Ask, What is the difference between a
meteor and a meteorite? (A meteor is a
meteoroid that burns when it enters
Earth’s atmosphere. A meteorite is part
of a meteor that doesn’t burn up
completely and hits the ground.)
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• Read the text about Pluto. Ask, What
fact about Pluto surprises you the
most? (Students may mention its
position changing with respect to
Neptune.)
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The last time Pluto moved inside
Neptune’s orbit was in February 1979.
Pluto stayed inside Neptune’s orbit until
February 1999. Now Pluto is back
outside Neptune’s orbit, and it will
remain the farthest planet from the Sun
until around 2230, when the switch will
happen again.
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• You may wish to share with students
that almost a hundred years passed
between the discovery of Neptune in
1846 and Pluto’s discovery in 1930.
Some scientists have discussed
whether Pluto should be called a
planet. Because of its relatively small
size, unusual orbit, and closeness to
the asteroid group known as the Kuiper
Belt, Pluto could be considered a dead
comet or a large asteroid. However,
there are currently no plans to change
Pluto’s official status as a planet.
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• If necessary, provide help with the
pronunciation of asteroids (ASS-tuhroids), meteoroids (MEE-tee-ur-roids),
meteor (MEE-tee-ur), and meteorite
(MEE-tee-ur-rite).
During certain times of the year, we
may be able to see more meteors, or
“shooting stars.” We call these clusters
of activity meteor showers. Meteor
showers happen when Earth passes
through trails of debris created by
comets as they pass by the Sun. The
particles of debris fall through Earth’s
atmosphere and burn up with a streak
of light that we can see. The last part of
the year is typically a strong time for
meteor showers. The Perseid (late July
to mid-August), Leonid (mid-November),
and Geminid (mid-December) meteor
showers all happen during this time.
© Delta Education. Photocopying and distribution prohibited.
Page 12 Neptune, Pluto
People in Science (page 14)
• One famous example of a crater on Earth
that is visible today is Meteor Crater near
Winslow, Arizona. This huge pit—1.2
kilometers (0.8 miles) wide and over 180
meters (600 feet) deep—is believed to
have been made by a meteorite that
crashed to Earth about 50,000 years ago.
Another example is Chubb Crater in
Canada. A 200-meter (820-feet) deep lake
fills this 1.4 million-year-old crater.
Adriana C. Ocampo, Planetary Geologist
• Ask whether students know what a
geologist is. If necessary, explain that a
geologist is a scientist who studies the
Earth and the Earth’s history as shown in
its layers of rock. Ask, What do you think
a planetary geologist is? (a scientist who
studies planets and other objects in our
Solar System; sometimes this helps
them learn more about Earth and Earth’s
history)
Did You Know? (page 15)
How Telescopes Work
• After reading the text on page 14, ask,
What is an impact crater? (the hole in the
ground made when a meteorite hits the
Earth’s surface) How do you think a
meteorite impact may have caused the
dinosaurs to become extinct? (Accept
reasonable responses.)
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Further Facts
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• Hypotheses about how the Chicxulub
impact may have caused the extinction of
the dinosaurs vary. Some scientists think
that gases, debris, and dust may have
clouded the Earth, causing changes in
Earth’s climate.
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• Have students read page 15 to determine
how the two types of telescopes work.
Ask, What is the difference between a
refracting telescope and a reflecting
telescope? (A refracting telescope uses
lenses to collect light; a reflecting
telescope uses mirrors. A refracting
telescope is more powerful than a
reflecting telescope of the same size.)
How is the way you look through the
telescopes different? (You look straight
through a refracting telescope; you look
into the side of a reflecting telescope.)
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• If necessary, provide help with the
pronunciation of Adriana Ocampo (aydree-AHN-na oh-KOMP-oh), geologist (jeeOL-uh-jist), Chicxulub (CHIK-shoo-loob),
and Yucatán (you-kuh-TAN).
Students may be interested to know that
one of the astronauts who walked on the
moon, Harrison Schmitt, is a geologist.
He collected Moon rocks on the last
Apollo mission to the Moon in 1972.
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• Direct students’ attention to the diagrams
of the refracting and reflecting telescopes.
Read the labels with students, and call on
volunteers to describe what they see.
• Ask, How does a telescope help us see
more stars than we can see with our
eyes alone? (A telescope’s lenses are
bigger and can gather more light than our
eyes can.)
• Earth is constantly being hit by space
debris, but most of it burns up before it
reaches Earth’s surface. Nevertheless,
some space scientists look for, track, and
categorize asteroids and comets that may
travel near Earth. A scale called the Torino
Scale has been developed to describe the
potential for collision with a comet or an
asteroid.
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• Galileo Galilei was the first to apply the
telescope to the study of the night sky.
Galileo published an account of his
explorations with the telescope,
Sidereus Nuncius (Starry Messenger),
in 1610.
• The largest optical telescope in the
world is located in Mauna Kea, Hawaii,
at the Keck Observatory. The telescope
sits on top of a dormant volcano. The
telescope is about 8 stories high, and its
primary mirror is 10 meters (32.8 feet)
across.
• Other large telescopes are located in
Chile at the Paranal Observatory. When
its four 8-meter-mirrored telescopes
work together, it is known as the VLT,
short for “Very Large Telescope.”
• The Hubble Space Telescope is in orbit
579 km (360 miles) above the Earth.
It was launched in 1990. Hubble is
not affected by conditions in Earth’s
atmosphere, such as clouds, pollution,
or light from cities, the way telescopes
on Earth are affected. It therefore can
provide sharp images of distant objects
in space.
AFTER READING
Summarize
Complete the KWL chart you began with
students before reading by asking them to
share the answers to their questions. Call
on volunteers to retell each text section.
Then have students use the information in
the KWL chart and the Planetary Facts table
to write brief summary statements.
Discuss with students how using the KWL
strategy helped them understand and
appreciate the book. Encourage them to
share any other reading strategies that
helped them understand what they read.
Direct attention to the fourth column in the
chart and ask, What questions do you still
have about the Solar System, its planets,
and other objects in the Solar System?
What would you like to explore further?
Record students’ responses. Then ask,
Where do you think you might be able to
find this information? (Students might
mention an encyclopedia, science books,
and the Internet.) Encourage students to
conduct further research.
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© Delta Education. Photocopying and distribution prohibited.
Further Facts
Review/Assess
Writing Links/Critical Thinking
Use the questions that follow as the basis for
a discussion of the book or for a written or
oral assessment.
Present the following as writing assignments.
1. What is the Solar System? (the Sun, the
planets, and other space objects that move
around the Sun)
1. In this book, the planets are divided into
two groups, the inner planets and the outer
planets. What is another way the planets
can be grouped? Explain how the planets in
each group are alike. (Students may
classify planets according to size or
composition, grouping the inner planets
and Pluto together. Other possibilities
include the length of a planet’s day, the
existence of rings, or large and small
numbers of moons.)
2. What are the names of the inner planets?
(Mercury, Venus, Earth, Mars) How are they
alike? (They all have hard, rocky surfaces.)
3. What are the names of the outer planets?
(Jupiter, Saturn, Uranus, Neptune, Pluto)
Except for Pluto, how are these planets
alike? (They are huge balls of glowing gas,
have many moons, and have rings.)
4. If you could travel to each planet in the
Solar System, which one would take you
the longest to reach? Why? (Pluto, because
it’s the farthest away from Earth.)
© Delta Education. Photocopying and distribution prohibited.
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2. What is the connection between Earth’s
axis and the seasons? (Earth’s axis is tilted.
Part of Earth points toward the Sun and
part of Earth points away from it. As Earth
moves around the Sun, some parts of Earth
get more direct sunlight than other parts
do. This causes the seasons.)
Science Journals: You may wish to have
students keep all the writing activities related
to the Delta Science Reader in their science
journals.
References and Resources
For trade book suggestions and Internet sites,
see the References and Resources section of
this teacher’s guide.
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