Elements of Earth Science
The Planet Earth
Teacher’s Guide
Grade Level: 6–12
Curriculum Focus: Earth Science
Lesson Duration: Two class periods
Program Description
Earth formed 4.6 billion years ago. Uncover the planet’s composition and structure, theories about how
the moon formed, and the influence the moon has on Earth. Discover why Earth’s magnetic field is
constantly changing, how it protects us from the harmful effects of the sun, and how the sun provides
energy for everyone and everything on our planet.
Onscreen Questions
How was Earth formed?
What is the structure of Earth?
What is the moon made of, and how was it formed?
How does the moon affect the tides?
What causes Earth’s magnetism, and why is it important?
How do we get energy from the sun, and how can there be so many different forms of energy?
Lesson Plan
Student Objectives
Understand how Earth formed.
Identify the crust, mantle, and inner and outer core of the Earth and their properties.
Write a news-style report about a probe being sent through the Earth.
Materials
The Planet Earth video
Computer with Internet access
Video camera and monitor, if available
Elements of Earth Science: The Planet Earth
Teacher’s Guide
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Procedures
1. Explain to students that they will be creating 3-4 minute news segments about an imaginary
probe traveling through Earth. The segments should be similar to how a TV science reporter
might cover the launch of a space probe.
2. Divide the class into groups and assign each group a layer of the Earth. (You may want to
divide the mantle into upper and lower sections, or assign a group to give a brief overview of
all the layers and how they were formed.) Using a globe, select an entrance point for the probe
and determine where it would exit Earth. If the probe is launched from a continent but exits in
an ocean what differences might it encounter in breaking through the crust?
3. Have students research their assigned layer. The following sites are good starting points for
exploring Earth’s layers online:
http://www.usgs.gov/science/science.php?term=292
http://mediatheek.thinkquest.nl/~ll125/en/struct.htm
http://scign.jpl.nasa.gov/learn/plate1.htm
http://pubs.usgs.gov/publications/text/inside.html
http://www.solarviews.com/eng/earthint.htm
http://www.palaeos.com/Earth/Geosphere/structure.htm
4. Students should look for answers to the following questions:
•
How thick is the layer?
•
What is its composition?
•
Is the layer liquid, solid, or semi-liquid? If the material is liquid or semi-liquid, what
affect does its movement have on the planet?
•
What is the temperature?
•
What is the significance of this layer?
5. After students have completed their research have each group compile their results into a report
that describes what the probe will encounter as it makes its way through a particular layer.
Here the students can get creative, giving the probe special features to force its way through
solid material and withstand extremely high temperatures.
6. Set up the video camera and have a representative of each group act as the on-camera reporter
to deliver the group’s findings to the class.
Published by Discovery Education. © 2005. All rights reserved.
Elements of Earth Science: The Planet Earth
Teacher’s Guide
Assessment
Use the following three-point rubric to evaluate students' work during this lesson.
3 points: Students were highly engaged in class discussions; conducted thorough research;
presented a creative and accurate report.
2 points: Students were somewhat engaged in class discussions; conducted adequate research;
presented an acceptable report.
1 point: Students were not engaged in class discussions; did not conduct adequate
research; did not present an acceptable report.
Vocabulary
crust
Definition: The topmost layer of Earth, composed essentially of crystalline rock
Context: Oceanic crust is much thinner than continental crust.
electromagnetic
Definition: Magnetism developed by a current of electricity
Context: The sun’s energy travels to Earth as electromagnetic waves that provide us with both
heat and light.
inner core
Definition: The solid, extremely dense innermost region of Earth
Context: Although the temperature of Earth’s inner core is about 7,000 degrees Celcius, it’s
under such tremendous pressure that it remains solid.
magnetosphere
Definition: The region of space surrounding Earth that is dominated by a magnetic field
Context: The magnetosphere deflects much of the solar wind, preventing particles from the sun
from hitting Earth.
mantle
Definition: The layer of Earth that lies beneath the crust and above the central core
Context: The mantle contains about 83 percent of Earth’s volume.
outer core
Definition: The layer of Earth located below the mantle
Context: The outer core is about the same temperature as the inner core, but because it is under
less pressure, it is molten.
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Elements of Earth Science: The Planet Earth
Teacher’s Guide
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photosynthesis
Definition: The process by which green plants and certain other organisms transform light into
chemical energy
Context: Life began on Earth about 3.8 billion years ago, when tiny a bacterium first used
photosynthesis to make its own food.
Standards
National Academy of Sciences
The National Academy of Sciences provides guidelines for teaching science in grades K–12 to
promote scientific literacy. To view the standards, visit this Web site:
http://books.nap.edu/html/nses/html/overview.html#content.
This lesson plan addresses the following national standards:
•
Earth and Space Science: Structure of the Earth system; Earth’s history
Mid-continent Research for Education and Learning (McREL)
McREL's Content Knowledge: A Compendium of Standards and Benchmarks for K-12 Education
addresses 14 content areas. To view the standards and benchmarks, visit
http://www.mcrel.org/compendium/browse.asp
This lesson plan addresses the following national standards:
•
Science: Earth and Space Sciences—Understands Earth's composition and structure
Support Materials
Develop custom worksheets, educational puzzles, online quizzes, and more with the free teaching tools
offered on the Discoveryschool.com Web site. Create and print support materials, or save them to a
Custom Classroom account for future use. To learn more, visit
•
http://school.discovery.com/teachingtools/teachingtools.html
Published by Discovery Education. © 2005. All rights reserved.
Elements of Earth Science: The Planet Earth
Teacher’s Guide
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DVD Content
This program is available in an interactive DVD format. The following information and activities are
specific to the DVD version.
How To Use the DVD
The DVD starting screen has the following options:
Play Video—This plays the video from start to finish. There are no programmed stops, except by
using a remote control. With a computer, depending on the particular software player, a pause
button is included with the other video controls.
Video Index—Here the video is divided into sections indicated by video thumbnail icons. Watching
all parts in sequence is similar to watching the video from start to finish. Brief descriptions and total
running times are noted for each part. To play a particular segment, press Enter on the remote for
TV playback; on a computer, click once to highlight a thumbnail and read the accompanying text
description and click again to start the video.
Curriculum Units—These are specially edited video segments pulled from different sections of the
video (see below). These nonlinear segments align with key ideas in the unit of instruction. They
include onscreen pre- and post-viewing questions, reproduced below in this Teacher’s Guide. To
play a particular segment, press Enter on the TV remote or click once on the Curriculum Unit title
on a computer.
Standards Link—Selecting this option displays a single screen that lists the national academic
standards the video addresses.
Teacher Resources—This screen gives the technical support number and Web site address.
Video Index
I. The History of the Earth (5 min.)
The Earth formed when gravity pulled galactic dust and gas into a core about 4.6 billion years ago.
Discover how different elements came together to form the planet.
Pre-viewing question
Q: How did the planets form?
A: Dust and gas left over from the sun’s formation began to come together. As an object got bigger,
its gravity increased and it drew in more material. The largest of these objects grew to be planets.
Post-viewing question
Q: What are some of the features that make Earth capable of supporting life?
A: Answers will vary, but the main two are the atmosphere of oxygen and nitrogen and the
abundance of water.
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Elements of Earth Science: The Planet Earth
Teacher’s Guide
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II. The Earth’s Structure (3 min.)
Earth is made up of several layers surrounding the solid inner core. Explore what’s happening right
under our feet.
Pre-viewing question
Q: What’s happening under Earth’s crust?
A: The Earth’s interior consists of several layers, each of varying temperatures and densities.
Post-viewing question
Q: What are the main layers of Earth?
A: The solid inner core, liquid outer core, mantle and crust. The crust and top part of the mantle are
called the lithosphere.
III. The Moon: Its Composition and Origins (5 min.)
The moon probably formed about the same time as Earth, but it is very different in composition and
structure. Learn more about Earth’s only natural satellite.
Pre-viewing question
Q: What is the moon made of and how was it formed?
A: Answers will vary.
Post-viewing question
Q: What is the impact theory?
A: It’s a theory on the origin of the moon. Scientists believe that not long after Earth formed, an
object about the size of Mars collided with it, throwing out rocky debris that went into orbit above
Earth. Gradually this debris gathered and became the moon.
IV. The Moon’s Influence on the Earth (4 min.)
Earth’s gravity holds the moon in orbit, but the moon’s gravity also affects Earth. Discover how the
moon causes the rise and fall of tides.
Pre-viewing question
Q: How does the moon affect Earth?
A: Answers will vary, but the most well known affect is the rise and fall of ocean tides.
Post-viewing question
Q: Why are tidal cycles not the same everywhere on Earth?
A: Earth is not evenly covered with water, and the coastlines and local conditions make tidal
patterns complicated. Winds and the sun also affect tides.
V. Earth’s Magnetic Field (5 min.)
Earth is similar to a magnet sending out lines of force that create a giant magnetic field around the
planet. Find out what this field tells us about Earth’s structure.
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Elements of Earth Science: The Planet Earth
Teacher’s Guide
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Pre-viewing question
Q: Why does a compass always point north?
A: A compass is a small magnet, while the Earth is a giant magnet. All magnets have two poles,
north and south. The magnet on the compass aligns with the north-south direction of Earth’s
magnetic field.
Post-viewing question
Q: How does the magnetosphere protect Earth?
A: It shields the planet from destructive solar winds, streams of gases, and particles that blow
outward from the sun.
VI. Energy From the Sun (6 min.)
The sun makes life on Earth possible. Explore how the sun's energy influences the climate and helps
plants create chemical energy that sustains the life of all plants and animals.
Pre-viewing question
Q: How do we get energy from the sun?
A: Answers will vary.
Post-viewing question
Q: What are some of the various forms of energy that ultimately come from the sun?
A: Chemical energy is created during photosynthesis, when plants convert electromagnetic energy
and store it in their tissues. Fossil fuel, such as gasoline, was formed from the remains of
microscopic marine animals that lived millions of years ago that originally got their energy from
the sun. Wind energy also comes from the sun, through atmospheric heating and cooling. Water
energy can be caused by waves, the friction between wind and water, or by evaporating moisture
created by the sun’s heat, that eventually falls as rain, creating rapids and waterfalls.
Published by Discovery Education. © 2005. All rights reserved.