Lesson 2:The Apollo Moon Rocks

Level: R
DRA: 40
Genre:
Informational
Strategy:
Question
Skill:
Text and Graphic Features
Word Count: 1,430
The Apollo
Moon Rocks
5.1.2
HOUGHTON MIFFLIN
Online Leveled Books
ISBN-13:978-0-547-02509-4
ISBN-10:0-547-02509-2
by Luna Fracchia
1032417
H O UG H T O N M IF F L IN
The Apollo
Moon Rocks
by Luna Fracchia
PHOTOGRAPHY CREDITS: Cover NASA/JSC, GPN-2000-001131. Title Page Eurelios/Photo Researchers, Inc. 3 Image
Ideas/Index Stock Imagery, Inc. 4 Mary Evans Picture Library/Photo Researchers, Inc. 5 John Sanford/Photo Researchers,
Inc. 6 (tl) NASA/JSC, GPN-2000-001889. (tr) NASAA/JSC, GPN-2000-000382. (b) StockTrek/Getty Images. 7 (tl) (tr) NASA,
GPN-2001-000012. (b) Photodisc/Getty Images. 8 (l) NASA/JSC, GPN-2000-001131. (r) NASA, GPN-2001-000014.
9 NASA. 11 Eurelios/Photo Researchers, Inc. 12 NASA, GPN-2001-000014. 14 NASA, s88_33651.
Copyright © by Houghton Mifflin Company. All rights reserved.
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Printed in China
ISBN-13: 978-0-547-02509-4
ISBN-10: 0-547-02509-2
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Table of Contents
An Age-Old Mystery
3
Our Knowledge Grows
4
More Questions to Answer
5
The First Humans on the Moon
6
Apollo 11’s Mission
7
More Missions to the Moon
9
Learning from Moon Rocks
10
How Is Earth Different?
12
Moon Rocks vs. Earth Rocks
13
More Mysteries to Solve
14
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An Age-Old Mystery
Since ancient times, the moon has been an
object of wonder. Many early peoples believed that
the moon was a god or a goddess. Others thought
that the moon had special powers. People had
endless questions about the glowing circle in the
night sky. Why does it seem to change shape?
Why does its path across the night sky change?
Who, if anyone, lives on the moon?
On a clear night, you can
see many features on the
surface of the moon.
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A Greek astronomer
named Hipparchus
realized that Earth
and the moon are
both shaped like balls,
and that the moon
orbits Earth.
Our Knowledge Grows
Ancient peoples studied the moon carefully.
Knowledge of the moon grew over time. Here
are a few things that people have figured out
about Earth’s closest neighbor.
• The moon has no light of its own. It reflects
the sun’s light.
• The moon orbits, or travels around, Earth. It
takes 29½ days for the moon to complete one
trip around Earth.
• We see only one side of the moon. That is
because the moon turns on its axis at the same
time that it circles Earth.
• As the moon orbits, it seems to change shape.
That is because different parts of the moon are
lit by the sun at different times. We see only
the lit part.
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More Questions to Answer
By the 1950s, people knew a lot about the
moon. But many questions were still unanswered.
People didn’t know what the moon was made of.
They didn’t know how old it was or how it came to
be. These questions could only be answered by
visiting the moon.
The Phases of the Moon
This diagram shows how the moon seems
to change shape from day to day as it
moves across the sky. As the moon orbits
Earth, Earth also orbits the sun. Different
amounts of light hit the moon on different
days. Because we only see the lit side of
the moon, it seems to change shape.
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The First Humans on the Moon
For centuries, people dreamed about traveling
to the moon. In 1969, this dream became a reality.
The American space mission Apollo 11 carried the
first human beings to the moon.
After a four-day trip through space, astronauts
Neil Armstrong and Edwin “Buzz” Aldrin, Jr.,
landed on the moon’s surface. A third astronaut,
Michael Collins, remained in orbit. Collins was
the operator of the command module. The
command module would take the astronauts home.
Timeline of Moon Exploration
1968
1964–1965
U.S. rockets
take the first
close-up TV
pictures of
the moon.
Apollo 8
astronauts
orbit the
moon 10
times but
do not land.
1950
1959
The Soviet
Union launches
a rocket aimed
at the moon.
1966
The Soviet Union
launches a rocket
that reaches the
moon.
1969
Apollo 11
astronauts
land on the
moon.
6
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Apollo 11’s Mission
The landing module remained on the moon’s
surface for 21 hours and 38 minutes. Outside the
module, the astronauts quickly adjusted to walking
on the moon. They had practiced on Earth in a
special room that could simulate weightlessness.
The astronauts spent more than two hours outside
the module on the moon’s surface. They had
several important jobs.
1998
1969–1972
Apollo missions
12, 14, 15, 16,
and 17 explore
the moon.
The U.S. space
probe Lunar
Prospector
finds frozen
water on the
moon’s poles.
2000
1970
The first unmanned
spacecraft collects
rock samples from
the moon.
1994
The U.S. space probe
Clementine takes
almost two million
photos of the moon.
7
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When astronaut Neil
Armstrong set foot on
the moon, his first
words became famous.
“That’s one small step
for [a] man, one giant
leap for mankind.”
During their moon walk, the astronauts were
busy. They took photographs of the moon’s surface.
They collected rock samples and did tests on the
moon’s dirt. They communicated with Mission
Control on Earth. They even talked with the
President of the United States.
Apollo 11 was a huge success. The astronauts
collected about 48 pounds of material. These
included 50 moon rocks and several samples of
moon dirt.
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More Missions to the Moon
The crew of Apollo 11 collected samples from
just one part of the moon. Scientists wanted
samples from other areas, too. Over the next four
years, five more Apollo missions carried astronauts
to the moon. The diagram below shows where
they landed.
Apollo 15
Apollo 17
Apollo 11
Apollo 12
Apollo 14
Apollo 16
The Apollo missions explored the middle
part of the moon, close to its equator.
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Learning from Moon Rocks
Altogether, the six Apollo missions brought
back about 840 pounds of moon rocks and dirt.
From studying these samples closely, scientists
have learned many things about the moon. Here
are some of the things they learned.
The moon is lifeless. No traces of plants or
animals have been found in the lunar soil.
Violent forces shaped the moon. The moon
is made of rocky material that was shot out of
volcanoes and smashed by meteorites. Meteorites
are chunks of material from space that crash into
planets. The meteorites caused deep, wide holes
called craters.
At one time, the moon nearly melted. Long ago,
a bubbling ocean of hot liquid rock covered much
of the moon’s surface. Mountains formed when
crusts in the liquid rock cooled.
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The moon is about 4.5 billion years old.
The youngest moon rock is older than the
oldest Earth rock.
The moon has a structure that is similar to
Earth’s. The moon has a thick crust. Earth also
has a crust, called the mantle. There are two layers
of rocks under the moon’s crust. Possibly, the
moon has an iron core at the center.
Earth and the moon are related. Earth and the
moon are made of the same basic rock materials.
But over time, different forces acted on these
materials. So today, most moon rocks appear to be
very different from the rocks found on Earth.
Many moon rocks were
created by volcanoes and
by meteorite impacts.
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For almost 40 years, this
footprint has remained
the same.
How Is Earth Different?
Twelve astronauts left their footprints on the
moon. Those footprints are still there. That is
because there is no wind on the moon. There is no
weather. The moon is shaped by forces outside
itself. Without outside forces, the moon would not
change at all.
Earth, on the other hand, is constantly
changing. Some changes happen slowly. For
example, forces deep inside Earth push rock
upwards. Over millions of years, the rock grows
into mountains. Over time, rain and wind wear the
mountains away.
Other changes happen quickly. Within weeks,
a volcano can bury a village or form a new island.
Within seconds, an earthquake can split the surface
open for many miles.
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Moon Rocks vs. Earth Rocks
Moon rocks do not change. But on Earth,
rocks are constantly changing. You can’t see
these changes as they happen because they happen
very slowly. The diagram below shows how rocks
can change.
Wind and rain hit a granite
mountain. Granite is a
metamorphic rock.
Bits of granite erode,
fall into a stream, and
are carried away.
1 Weathering
7
2
Erosion
The cycle
begins again.
Metamorphic
rock
“New” rock
may push to
the surface.
Heat and pressure
may change the
sedimentary rock into
metamorphic rock.
6
The bits of rock
are deposited in a
lakebed. They mix in
with sand, mud, and
plant remains.
3 Deposition
Bu
he
ria
ati
l
ng
, sq
ua
shi
ng
5
Sedimentary
rock
4
Layers pile up.
Pressure causes
the bits of granite
to slowly change
into sedimentary
rock.
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More Mysteries to Solve
The Apollo moon rocks have helped scientists
learn a great deal about the moon. But there are
more mysteries to solve.
Scientists plan to return to the moon before
the year 2020. Next time, humans will be there
to stay. Scientists hope to set up a space station
on the moon. Astronauts will live there for
months at a time. The space station will help
scientists see how humans function in space. It
will also allow astronauts to study the moon more
closely than ever.
A future outpost on the moon may look
something like this.
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Responding
Text and Graphic Features
What can the Table of Contents tell you? How can
the timeline on pages 6 and 7 help you understand
the story? Copy and complete the chart below.
TARGET SKILL
Text Feature
Purpose
Table of Contents
shows the different
parts of the story
timeline
?
Write About It
Text to World In 1969, the Apollo 11 space mission
brought the first humans to the moon. Write a
paragraph telling a story about something interesting
you have observed while looking at the moon.
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TARGET VOCABULARY
acute
function
adjusted
operator
axis
simulate
delicate
tethered
flawed
version
TARGET SKILL Text and Graphic Features Examine
how the arrangement of text and visuals makes ideas
clearer.
TARGET STRATEGY Question Ask questions about
a selection before you read, as you read, and after you
read.
GENRE Informational Text gives facts and examples
about a topic.
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Level: R
DRA: 40
Genre:
Informational
Strategy:
Question
Skill:
Text and Graphic Features
Word Count: 1,430
The Apollo
Moon Rocks
5.1.2
HOUGHTON MIFFLIN
Online Leveled Books
ISBN-13:978-0-547-02509-4
ISBN-10:0-547-02509-2
by Luna Fracchia
1032417
H O UG H T O N M IF F L IN