Download Exploring Space—The Universe: The Vast

Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
Grade Level: 5-9
Curriculum Focus: Science
Lesson Duration: 5 class periods
Program Description
Measuring the Universe: The Light-Year (5 min.)—Explains what a light-year is and its use in measuring
distances in outer space. Galaxies (2 min.)—Describes different types of galaxies including our own
galaxy, the Milky Way. The Life Cycle of Stars (7 min.)—Provides an overview of stars’ life cycles, and
explains nuclear fusion’s role in their evolution. Star Color (2 min.)—Explains how scientists determine
stars’ approximate temperatures. Dark Matter (1 min.)—Introduces the unexplained matter that
comprises 90 percent of the universe. The Big Bang (5 min.)—Explains the Big Bang theory and the
expansion of the universe.
Discussion Questions
•
What is a light-year?
•
What are the three types of galaxies?
•
How are stars formed?
•
When did the “Big Bang” occur?
Lesson Plan
Student Objectives
•
Explain how galaxies are created
•
Research and be able to accurately describe the life cycle of stars
•
Analyze and share their understandings about the Big Bang theory
•
Research and write a two-page report about a heavenly body or system in the universe
•
Create a presentation for the class based on the subject matter of the two-page report
Materials
•
Exploring Space—The Universe: The Vast Reaches of Space video
•
Computer with Internet access
•
Print and Web resources about scientific exploration of the universe
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
•
2
Poster boards (one per student), tape, and markers for class presentations
Procedures
1. Before viewing the video, ask students what interests them most about the universe. Is it the
enormous distances? The idea of planets and galaxies far different than our own? Do they believe
that there is life in other parts of the universe? Do they believe that our country and other nations
should continue to explore outer space? Inform the students that they will be viewing a program
about the various entities that make up the universe.
2. After viewing the program, discuss how distances are measured in outer space. What is a lightyear? Explain that a light-year is the distance light travels in one Earth year. What is the closest
star to our planet besides the sun? (Proxima Centauri.) How far away is Proxima Centauri from
our planet? (Proxima Centauri is 4.3 light-years, or 26 trillion miles, away from Earth.)
3. Discuss with students the location of the solar system within the Milky Way galaxy. What are the
three types of galaxies? Discuss answers from the video. (The universe contains spiral, elliptical,
and irregular galaxies.) What type of galaxy is the Milky Way (A spiral galaxy.) Do they think
there are types of galaxies that have not yet been discovered? How are galaxies created? Explain
that spiral galaxies form from the collapse of a protogalactic cloud, whereas elliptical galaxies are
formed as a result of a merger between two disk galaxies.
4. Review with students the life cycle of a star. How are stars formed? (A star is born when gravity
pulls hydrogen gas from a nebula into a spinning cloud. The resulting nuclear reaction and
nuclear fusion keep the star evolving.) How old is the sun? (Approximately 5 billion years old.)
What happens when stars get older? What is a supernova? What do students think will happen to
the Earth billions of years from now when the sun expands into a red giant and eventually
becomes a dead star?
5. Discuss the Big Bang theory with the class. According to scientists, when did the “Big Bang”
occur? (12 to 13 billion years ago.) How has the Hubble telescope been able to prove this theory?
Explain how the Hubble telescope has been able to detect that galaxies are gradually moving
away from each other. What does it mean when scientists say they have detected a redshift in the
color of the galaxies? Discuss answers from the video. (As wavelengths of light spread out, their
color appears on the red end of the visible spectrum.) Does this mean that the universe is getting
bigger?
6. Assign each student a topic related to one aspect of the universe (for example, a white dwarf star,
a supernova, or a black hole). Students will write a two-page report on their assigned topic, citing
at least three relevant facts about their topic. The following Web sites contain relevant data:
•
Universe (Wikipedia)
http://en.wikipedia.org/wiki/universe
•
BBC Science and Nature (Space)
www.bbc.co.uk/science/space/solarsystem
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
•
3
Kidsastronomy.com
www.kidsastronomy.com/universe.htm
•
Curious About Astronomy? Ask an Astronomer (Cornell University)
http://curious.astro.cornell.edu/index.php
•
Exploring the Universe (NASA)
www.nasa.gov/vision/universe/features
•
Imagine the Universe (NASA)
http://imagine.gsfc.nasa.gov
•
Universe Forum Learning Resources (Harvard University)
http://cfa-www.harvard.edu/seuforum/learningresources.htm
7. Based on the content of their reports, each student will create a “What Am I?” presentation and
deliver it to the entire class. The students will reveal several facts about their subject matter and
ask their classmates to guess what they are describing. Distribute the poster board to students and
ask them to fold their boards in half. They are to write their clues on the front of their folded
poster board and write the answer (with an appropriate illustration or graphic) on the “inside” of
the folded board.
Assessment
Use the following three-point rubric to evaluate students' work during this lesson.
•
3 points: Students produced a complete report and individual project, included all of the
requested information in the report and the in-class presentation; accurately cited three
interesting, relevant points in their report and during their presentation.
•
2 points: Students produced an adequate report and individual project, included most of the
requested information in the report and the in-class presentation; satisfactorily cited two
relevant points in their report and during their presentation.
•
1 point: Students created an incomplete report and individual project, included little or none
of the requested information in the report and the in-class presentation; did not cite any
relevant points in their report or during their presentation.
Vocabulary
black hole
Definition: An invisible region believed to exist in space having a strong gravitational field;
thought to be caused by the collapse of a star
Context: The gravity of a black hole is so strong that nothing nearby can escape being pulled into
it.
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
4
comet
Definition: A bright heavenly body that develops a cloudy tail as it moves closer to the sun in its
orbit
Context: Comets are also called shooting stars because of the streak of light created as the comet
burns n the Earth’s atmosphere.
galaxy
Definition: One of the very large groups of stars and other matter that are found throughout the
universe
Context: The Milky Way is a spiral-shaped galaxy.
light-year
Definition: A unit of measurement in astronomy equal to the distance that light travels in one year
Context: A light-year is equivalent to 5,880,000,000,000 miles.
nebula
Definition: Any of many huge clouds of gas or dust in deep space
Context: The Helix Nebula—the closest planetary nebula to Earth—is 450 light-years away.
planet
Definition: A heavenly body other than a comet, asteroid, or satellite that travels in orbit around
the sun
Context: There are nine planets in our solar system.
pulsar
Definition: A neutron star that emits rapid and periodic pulses of radiation
Context: A pulsar gives off radio waves due to the lack of synchronization between its rotation
axis and its magnetic axis.
star
Definition: A massive, ball-shaped gaseous celestial body that shines by its own light
Context: Compared to other stars in the universe, the sun is relatively young.
supernova
Definition: The explosion of a very large star in which the star temporarily gives off up to one
billion times more energy than the sun
Context: The Hubble Space Telescope has obtained the clearest images of a supernova.
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
5
spectrum
Definition: The grouping of colors including red, orange, yellow, green, blue, indigo, and violet
arranged in the order of their wavelengths and seen when white light passes through a prism
Context: Each element creates its own distinct spectrum.
Academic Standards
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 program addresses the following national standards:
•
Science—Nature of Science: Understands the nature of scientific knowledge; Understands the
nature of scientific inquiry; Understands the scientific enterprise
•
Science—Earth and Space Science: Understands the composition and structure of the universe
and the Earth’s place in it
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:
•
Science as inquiry: Abilities necessary to do scientific inquiry; Understandings about scientific
inquiry
•
Earth and space science: Structure of the Earth system; Earth’s history; Earth in the solar system
•
Science and technology: Abilities of technological design; Understandings about science and
technology
•
History and nature of science: Science as a human endeavor; Nature of science; History of science
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
6
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
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; brief
descriptions are noted for each one. Watching all parts in sequence is similar to watching the video
from start to finish. 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. Total
running times for these segments are noted. 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. Measuring the Universe: The Light-Year (5 min.)
When we see stars in the sky we are looking at light that was emitted years ago. Discover what a lightyear is and how it is used as a measurement in space.
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
7
II. Galaxies (2 min.)
Scientists have identified three kinds of galaxies. Find out more about elliptical and irregular galaxies, as
well as spiral galaxies such as our own Milky Way.
III. The Life Cycle of Stars (7 min.)
Stars are created when gravity pulls hydrogen gas from the nebula into a spinning cloud. Learn more
about how stars evolve and die out, or explode into a supernova.
IV. Star Color (2 min.)
In outer space, the hottest stars are blue, while the coolest stars are red. Learn how scientists use a
spectroscope to gather information about stars.
V. Dark Matter (1 min.)
Scientists believe that dark matter makes up about 90 percent of the universe. Discover the important role
that dark matter plays in holding galaxies together.
VI. The Big Bang (5 min.)
The most popular scientific theory about the origin of the universe is called the Big Bang. Learn how the
Doppler effect provides evidence that the universe is still expanding.
Curriculum Units
1. The Light-Year as a Unit of Measurement
Pre-viewing question
Q: How do scientists measure distances in space?
A: Answers will vary.
Post-viewing question
Q: What is the speed of light?
A: The speed of light is 186,000 miles (or 300,000 kilometers) per second.
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
8
2. Galaxies
Pre-viewing question
Q: What is the name of the galaxy where our solar system is located?
A: The Milky Way.
Post-viewing question
Q: What are the three types of galaxies?
A: The three types of galaxies are spiral (like the Milky Way), elliptical, and irregular
3. The Birth and Death of Smaller Stars
Pre-viewing question
Q: What do you know about the sun?
A: Answers will vary.
Post-viewing question
Q: What will happen to the sun after its supply of hydrogen is nearly used up?
A: Over the course of billions of years, the helium core of the sun will begin to shrink, and the helium
atoms will fuse to form carbon atoms. The sun’s hydrogen outer shell will expand until the sun becomes
a red giant, before collapsing into a white dwarf and, eventually, a dead star.
4. Supernovas
Pre-viewing question
Q: What do you know about supernovas?
A: Answers will vary.
Post-viewing question
Q: What is a pulsar?
A: A pulsar is a neutron star that emits “pulses” or beams of high-energy radiation.
Published by Discovery Education. © 2006. All rights reserved.
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
5. The Light Spectrum
Pre-viewing question
Q: What is a spectrum?
A: Answers may include the colors of a rainbow.
Post-viewing question
Q: From hottest to coolest, what are the color classifications of stars?
A: Blue stars are hottest, followed by white, orange, yellow, and red, red being the coolest.
6. Detecting Dark Matter
Pre-viewing question
Q: What lies between the stars and planets in a galaxy?
A: Answers will vary.
Post-viewing question
Q: Based on current scientific knowledge, what purpose does dark matter serve?
A: Dark matter provides the gravity needed to keep a galaxy together.
7. The Big Bang Theory
Pre-viewing question
Q: What do you know about the Big Bang theory?
A: Answers will vary.
Post-viewing question
Q: According to the Big Bang theory, how old is the universe?
A: The universe is estimated to be 12 to 13 billion years old.
8. Gathering Information About the Universe
Pre-viewing question
Q: How do scientists gather information about the universe?
A: Answers may include shuttle missions, the space station, telescopes, and space probes.
Published by Discovery Education. © 2006. All rights reserved.
9
Exploring Space
The Universe: The Vast Reaches of Space
Teacher’s Guide
Post-viewing question
Q: What is the difference in wavelengths between high-pitched sounds and low-pitched sounds?
A: High-pitched sounds have wavelengths that are close together, while low-pitched sounds have
wavelengths that are more spread out.
Credit
Robyn Kurth, freelance writer
Published by Discovery Education. © 2006. All rights reserved.
10
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 1
Pre-Test
Name ______________
Directions: Answer the following questions in the space provided.
1.
What is a light-year?
2.
Define these terms:
a. nebula
b. Supernova
c. Galaxy
d. Milky Way
3.
When we look into the night sky we are actually looking into the past. How do you
explain that?
4.
What is the nuclear fusion reaction that takes place in the core of the sun?
5.
What is the solar wind?
6.
What is the Big Bang theory?
7.
What is a black hole?
8.
Why is a telescope orbiting the Earth a better location for observations than a landbased telescope on top of a mountain?
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 2
Program Quiz
Name ______________
1. What is the Big Bang theory?
2. Why do stars look so small to us?
3. What is dark matter?
4. Stars go through a life cycle. What is the expected outcome for our star, the sun, in five
billion years?
5. How do scientists use a spectroscope to gather information about a star?
All rights to print materials cleared for classroom duplication and distribution.
Name ______________
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 3
Vocabulary
Directions: Pick the definition in column II that best matches the word in column I. Write the
letter of the definition on the blank line.
I
1. light-year _______
2. sunspots _______
3. solar system _______
4. galaxy _______
5. supernova _______
6. nebula ______
7. nuclear fusion _______
8. spectroscope _______
9. black hole _______
10. solar wind _________
II
a. A cloud of gas that is known as the
birthplace of stars
b. Hydrogen atoms combine to make helium
atoms
c. Areas of strong magnetic activity on the
sun
d. A huge group of stars
e. The remains of an enormous star that has
erupted in a supernova explosion and then
collapsed in on itself
f. The explosion of a star
g. A measure of distance used by astronomers
h. Made up of a star or two and other bodies
that orbit the star or stars.
i. Electronically charged particles that spray
out from the sun causing problems with
radio transmissions and power failures on
Earth
j.
An instrument used to break light into
parts for analysis
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 4
The Hubble Telescope
Name ______________
The Hubble telescope was designed to help astronomers see deep into the universe and possibly
far enough back in time to collect information about the beginning of the universe.
1. How is it possible that a telescope can see back into time?
2. Why is having a telescope in Earth orbit better than a ground-based telescope?
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 5
Scientific Notation—Page 1
Name ______________
The numbers used to describe distances in space are huge. To make things easier to work with,
astronomers use scientific notation to represent these large numbers. It is like a numeric
shorthand or abbreviation. The system is based on multiples of ten and can be used to represent
large or small numbers. Here are some examples of scientific notation:
100 could be written as 10 x 10, or in scientific notation as 102.
The 2 is called an exponent of 10. It could be read as ten to the second power or
ten to the second.
10,000 could be written as 10 x 10 x 10 x10, or in scientific notation as 104,
(ten to the fourth power or ten to the fourth).
50,000 could be written as 5 x 104.
234,035 could be written as 2.34035 x 105.
To change large numbers into scientific notation, simply count from the decimal point to
the first digit. There are five digits between where the decimal point in 234,035 is located
and the first digit, which is the digit 2. Therefore, the scientific notation would be 2.34035 x
105.
Write these numbers in scientific notation:
a. 100,000 =
b. 3,000 =
d. 244,000 =
e. 2,345,000 =
Change these numbers from scientific notation:
b. 3 x 104 =
a. 106 =
d. 1.002 x 105 =
e. 5 x 109 =
c. 60,000 =
f. 45,000 =
c. 2.34 x 104 =
f. 3.4 x 104 =
Small numbers can also be represented in scientific notation. To change a number less than zero
to scientific notation, count the number of zeros after the decimal point to the first nonzero digit
and then add one. Here is an example: 0.00045 is written 4.5 x 10-4. (The – symbol in front of the
four tells us that this is a negative or less than one number). The number is read as four point five
times ten to the minus four.
Change these numbers to scientific notation:
a. 0.00003 =
b. 0.058 =
c. 0.003056 =
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 6
Scientific Notation—Page 2
Name ______________
Multiplication and division with scientific notation is easy to do because you only need to work
with the exponents and you use addition and subtraction instead of multiplication and division.
Here is how it works:
To multiply 30,000 times 2,000 follow these steps:
Step 1: Change the numbers to scientific notation.
30,000 = 3 x 104
2,000 = 2 x 103
Step 2: multiply the 3 and 2 to get 6
Step 3: add the exponents 4 and 3 to get 7
So the answer is 6 x 107
To divide 40,000,000 by 0.002 follow these steps:
Step 1: change the numbers to scientific notation.
40,000,000 = 4 x 107 0.002 = 2 x 10-3
Step 2: divide the 4 by 2 to get 2
Step 3: subtract the exponents 7-(-3) = 10
So the answer is 2 x 1010
Solve these problems using the scientific notation method:
1. 500,000 x 5,000
2. 500,000 / 5,000
3. 70,000 x 20,000
4. 6,000,000,000/2,000
5. 6,000,000,000 x 200,000
Change these numbers from scientific notation:
1. average Earth-sun distance 1.5 x 1011m
2. average Earth-moon distance 3.84 x 108m
3. diameter of the sun 1.39 x 106km
4. mass of the sun 1.99 x 1027 tons
5. mass of the Earth 5.976 x 1021 tons
6. mass of a neutron 1.6749 x 10-27 kg
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 7
A Light-Year
Name ______________
Distances are so great in space that a special unit of measurement is used. It is called a
light-year. This sounds like a measurement of time, but it is a unit used to measure
distance. By definition a light-year is the distance that light travels in one year. To calculate
the distance of one light-year, you determine the number of seconds in a year and then
multiply that number times the speed of light. Light is the fastest thing we know of, as it
travels at an incredible 186,000 miles (300,000 kilometers) per second.
Your job is to calculate the value of one light-year.
Calculate the number of seconds in one year.
Calculate the number of miles, or kilometers, in a light-year by multiplying the number
of seconds in a year by 186,000 miles, or 300,000 km.
Now that you know how many miles or kilometers are in a light-year, determine the
distance of these objects (round light-year to nearest trillion):
1. The closest star to Earth other than the sun is 4.3 light-years away.
2. The Andromeda galaxy is 2.2 million light-years away from Earth.
3. The diameter of the Milky Way galaxy is 100,000 light-years.
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 8
Emission Spectra
Name ______________
Everything in the universe is made of elements called the building blocks of matter. There are
just over one hundred natural or man-made elements. Each element has its own special spectral
lines. This makes it possible to identify what elements are present when looking at the spectral
lines given off by the light from stars.
For example here are the spectral lines for some elements:
hydrogen
helium
strontium
calcium
Here is an emission spectrum containing two of the above elements. Which two
elements are represented?
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 9
Fill in the Blanks
Name ______________
Directions: Use the words from the box to fill in the blanks in the following paragraphs.
Some words from the box will not be used.
The Doppler Effect
Scientists know that ________ are moving away from each other because of a ____ shift in
their color. This is called the _______ ______. We can demonstrate this effect using sound.
Light and sound travel in ____________ of varying size. _____ sounds have wavelengths
that are close together. ____ sounds have wavelengths that are more spread out. When an
ambulance or police car is coming toward you the wavelengths are pushed ______
together and the sound is _____ pitched. But as the vehicle passes and moves away from
you, the wavelengths _______ ____ and the pitch is lower.
Light will do the same thing. As the light moves away from us it becomes elongated and
shifts to the _______ wavelengths or the ___ end of the visible _________. Scientists have
seen the ____ shift with all the _______ observed so far. Therefore, everything is moving
away or expanding outward. No one knows if the expansion will continue, or whether it
will slow down and stabilize, or whether it will ________ itself.
Police
reverse
high (2)
longer
wavelengths
blue
low
large
science
red (3)
shift
pitch
far
galaxies (2)
spread out
visible
loud
theory
spectrum
longer
sound
close
shorter
green
Doppler Effect
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 10
Life Cycle of Stars
Name ______________
Directions: Use the diagram to help you describe the stages in the life cycle of a star. Write your
explanation on a separate sheet of paper.
Main Sequence
Red Giant
Formation
Lower Mass
Star
Massive Star
White Dwarf
High Mass
Neutron Star
Black Hole
Very High Mass
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 11
Fusion
Name ______________
The unbelievable energy and power produced by stars, such as the sun, comes from nuclear
fusion. Fusion occurs when atoms of lightweight elements unite, or combine, to form larger
atoms. During this process a tremendous amount of energy is released. The basic fusion reaction
that takes place in stars is fueled by hydrogen atoms that fuse to make helium atoms. Elements
are the building blocks of all matter. Elements are made of only one kind of substance. Each
element has its own makeup of protons, neutrons, and electrons. A hydrogen atom has one
proton and one electron. A helium atom has two protons, two neutrons, and two electrons. A
lithium atom has three protons, three neutrons, and three electrons. This continues throughout
all the known elements, different numbers of protons, neutrons, and electrons identify each
unique element. There are just over one hundred elements.
Elements have the same number of protons and electrons so that their electrical charges are
balanced. Protons have a positive (+) charge and electrons have a negative (-) charge. Neutrons
have no charge.
Within a star gravity exerts tremendous pressure the star’s core produces extremely high
temperatures. Temperatures in our sun’s core reach 15,000,000 degrees Kelvin. Under these
conditions hydrogen atoms fuse, or join, to make helium. Fantastic quantities of energy are
released during this process.
+
+
hydrogen + hydrogen
equals
helium
+
ENERGY
On Earth we can’t duplicate the gravity or temperatures found inside the sun. Scientists are
working on a different approach to generating energy from fusion.
Directions: Find out more about nuclear fusion by investigating one of the following questions:
¾ How are scientists attempting to use nuclear fusion to generate energy?
¾ How is nuclear fusion different from nuclear fission?
¾ Why would nuclear fusion be an important breakthrough for the future?
¾ What is a tokamak?
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 12
Post-Test
Name ______________
Directions: Answer the following questions in the space provided.
1. What is a light-year?
2. When you look into the night sky you are looking into the past. Explain this
statement.
3. How does the sun produce the tremendous amount of energy it releases every
second?
4. What is the solar wind?
5. Explain why a land-based telescope is not always an effective observation tool.
6. What is a black hole?
7. What is the Big Bang theory?
8. Define the following terms:
a. nebulae
b. supernova
c. galaxy
d. solar system
e. Milky Way Galaxy
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Masters Answer Key
Blackline Master 1—Answer Key
Pre-Test
1.
What is a light-year?
A light-year is the distance that light travels in one year. Light travels
300,000 km, or 186,000 mi, per second. A light-year is a measurement
used to measure distances in space.
2.
Define these terms:
a. nebula
A nebula is the gaseous birthplace of stars.
b. supernova
A supernova is the explosion of a star.
c. galaxy
A galaxy is a collection of billions of stars held together by gravity.
d. Milky Way
The Milky Way is the galaxy in which our solar system is found.
3.
When we look into the night sky we are actually looking into the past.
How do you explain that?
Distances in space are so huge that it takes the light from stars a long
time to travel to Earth. The closest star to Earth other than the sun is
4.3 light-years away. It takes the light 4.3 years to travel from that star
to the Earth. So the light we see from that star left there 4.3 years ago.
4.
What is the nuclear fusion reaction that takes place in the core of the
sun?
Nuclear fusion is what powers the stars. The tremendous heat and
pressure in the cores of stars causes hydrogen atoms to combine to
make helium atoms. In the process a great deal of energy is released.
5.
What is the solar wind?
The solar wind is made up of light particles released in all directions
from the sun. These radioactive particles travel to the outer planets.
6.
What is the Big Bang theory?
All rights to print materials cleared for classroom duplication and distribution.
The Big Bang Theory describes the beginning of the universe. It says
that all the matter of the universe once occupied a space no larger
than an atom. Then it burst forth and expanded outward, providing
the building blocks for everything in the universe.
7.
What is a black hole?
A black hole is the remains of a supergiant star that has collapsed
upon itself with such force that not even light can escape its
gravitational pull.
8.
Why is a telescope orbiting the Earth a better location for observations
than a land-based telescope on top of a mountain?
The images from telescopes on Earth are filtered through the particles
in our atmosphere. Clouds can make it impossible to view the stars.
Dirt and dust in the atmosphere can make viewing difficult. In space a
telescope provides a clearer picture because the image isn’t viewed
through an atmosphere of gases.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 2—Answer Key
Program Quiz
1. What is the Big Bang theory?
The Big Bang Theory describes the beginning of the universe. It says that
all the matter of the universe once occupied a space no larger than an
atom. Then it burst forth and expanded outward, providing the building
blocks for everything in the universe.
2. Why do stars look so small to us?
Stars look small because they are so far away. Most stars are much larger
than our own star, the sun. The sun is so big it could hold a million
planets the size of Earth.
All rights to print materials cleared for classroom duplication and distribution.
3. What is dark matter?
Observations of the way galaxies move and spin suggest that they are
made up of a lot more matter than we can detect. Black, or dark, matter is
that matter that we can’t see or detect.
4. Stars go through a life cycle. What is the expected outcome for our star,
the sun, in five billion years?
The sun will eventually increase in size as a red giant. It will expand to the
orbit of Earth and then shrink to a planet-sized white dwarf.
5. How do scientists use a spectroscope to gather information about a star?
Elements are the building blocks of all matter. Each element has its own
signature spectrum. White light is broken into a rainbow of colors when it
bends through a prism. A spectroscope can be used to analyze the light
given off by a star. It breaks the light into spectral lines that can be
compared with the known spectral lines of elements.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 3—Answer Key
Vocabulary
1. light-year _g_____
2. sunspots _c_____
3. solar system _h_____
4. galaxy _d_____
5. supernova _f_____
6. nebula _a____
7. nuclear fusion _b_____
All rights to print materials cleared for classroom duplication and distribution.
8. spectroscope _j_____
9. black hole _e_____
10. solar wind __i______
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 4—Answer Key
The Hubble Telescope
1. How is it possible that a telescope can see back into time?
The universe is so huge that the light from distant stars and galaxies take
hundreds, thousands, millions, and billions of light-years to reach Earth.
The unit of measurement in the universe is the light-year. It is the distance
light travels in one year. Light travels at the incredible speed of 186,000
miles, or 300,000 kilometers, per second. So the distance light travels in a
year is equal to almost 6 trillion miles. The closest star to Earth other than
the sun is 4.3 light-years away. So if that star explodes tonight we won’t
see the explosion for another 4.3 years.
2. Why is having a telescope in Earth orbit better than a ground-based
telescope?
A telescope in Earth orbit doesn’t face the problems that a ground-based
telescope has to deal with on a regular basis. The telescope in orbit is
above the atmosphere so clouds and dust don’t get in the way. Light
going through our atmosphere can be scattered, which makes obtaining
clear pictures difficult.
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 5—Answer Key
Scientific Notation—Page 1
Write these numbers in scientific notation:
b. 3 x 103
c. 6 x 104
a. 105
d. 2.44 x 105 e. 2.345 x 106
f. 4.5 x 104
Change these numbers from scientific notation:
a. 1,000,000 b. 30,000
c. 23,400
d. 100,200
e. 5,000,000,000
f. 34,000
Change these numbers to scientific notation:
a. 3 x 10-5
b. 5.8 x 10-2
c. 3.056 x 10-3
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 6—Answer Key
Scientific Notation—Page 2
Solve these problems using the scientific notation method:
1. 5 x 105
2. 5 x 105
3. 7 x 104
4. 6 x 109
5. 6 x 109
x 5 x 103
/ 5 x 103
x 2 x 104
/ 2 x 103
x 2 x 105
25 x 108
1 x 102
14 x 108
3 x 106
12 x 1014
2,500,000,000
100
1,400,000,000
3,000,000
1,200,000,000,000,000
Change these numbers from scientific notation:
1. 150,000,000,000 m
2. 384,000,000 m
3. 1,390,000 km
All rights to print materials cleared for classroom duplication and distribution.
4. 1,990,000,000,000,000,000,000,000,000 tons
5. 5,976,000,000,000,000,000,000 tons
6. 0.0000000000000000000000000016749 kg
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 7—Answer Key
A Light-Year
Calculate the number of seconds in one year.
Seconds in an hour: 60 x 60 = 3600
Seconds in a day: 24 x 3600 = 86,400
Seconds in a year: 365 x 86,400 = 31,536,000
Calculate the number of miles, or kilometers, in a light-year by multiplying the
number of seconds in a year by 186,000 miles, or 300,000 km.
Miles in a light-year: 186,000 x 31,536,000 = 5,865,696,000,000
Scientists round it off to 6 trillion.
In kilometers:
300,000 x 31,536,000 = 9,460,800,000,000 kilometers
Scientists round it to 9 trillion km.
Determine the distance of these objects (round light-year to nearest trillion):
1. The closest star to Earth other than the sun is 4.3 light-years away.
25.8 trillion miles
38.7 trillion km
2. The Andromeda galaxy is 2.2 million light-years away from Earth.
13.2 quintillion miles
19.8 quintillion km
3. The diameter of the Milky Way galaxy is 100,000 light-years.
600,000 trillion miles
900,000 trillion km
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 8—Answer Key
Emission Spectra
Here is an emission spectrum containing two of the above elements. Which two
elements are represented?
Hydrogen and helium
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 9—Answer Key
The Doppler Effect
Scientists know that galaxies are moving away from each other because of a red
shift in their color. This is called the Doppler Effect. We can demonstrate this
effect using sound. Light and sound travel in wavelengths of varying size. High
sounds have wavelengths that are close together. Low sounds have wavelengths
that are more spread out. When an ambulance or police car is coming toward
you the wavelengths are pushed close together and the sound is high pitched.
But as the vehicle passes and moves away from you, the wavelengths spread out
and the pitch is lower.
Light will do the same thing. As the light moves away from us it becomes
elongated and shifts to the longer wavelengths or the red end of the visible
spectrum. Scientists have seen the red shift with all the galaxies observed so far.
Therefore, everything is moving away or expanding outward. No one knows if
the expansion will continue, or whether it will slow down and stabilize, or
whether it will reverse itself.
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 10—Answer Key
Life Cycle of Stars
Stars form in gas clouds called nebulae. Gravity pulls more and more of this gas
together and the temperature increases. When it reaches 20 million degrees, a
nuclear reaction begins. Hydrogen atoms combine, or fuse, to form helium
atoms—releasing huge amounts of energy in the form of light and heat in all
directions. The star is born. How long a star takes to evolve is determined by its
mass. The more massive the star, the shorter its life. A star about the size of our
sun will live for around ten billion years. Eventually the supply of hydrogen is
almost used up. The core, which is mainly helium, shrinks and, as a result, heats
up causing helium atoms to fuse and form carbon atoms. The hydrogen outer
shell expands to an enormous size. At this point the star is considered a red
giant. Then the star will blow away its outer atmosphere and collapse to what is
called a white dwarf. The star shrinks to planet size and gives off white, cool
light.
A more massive star goes through a different death. When a star that is many
times larger than our sun turns into a red giant or a supergiant it doesn’t evolve
into a white dwarf. Instead, because of its terrific gravity, it fuses the carbon
atoms made from fused helium atoms into heavier elements. In other words, the
star continues to carry on fusion and produces heavier and heavier elements. By
the time the core of the star is mainly made up of iron atoms, it stops the fusion
process. Then the star explodes in a violent explosion called a supernova. The
elements, gases, and dust of the star explode into space to form a new nebula.
This nebula could become the birthplace for a whole new group of stars.
The core of a star that has exploded in a supernova ends up as either a neutron
star or a black hole depending on its original mass. Stars that are 6 to 30 times
more massive than our sun turn into a neutron star. Neutron stars are very
massive. If the star was originally 30 or more times larger than our sun the fate of
the core is very strange. After the supernova explosion the core is so heavy and
the gravity so strong that the star is pulled in on itself to form what is called a
black hole. A black hole has such strong gravity that everything that comes near
is swallowed into it. Not even light can escape a black hole.
All rights to print materials cleared for classroom duplication and distribution.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 11—Answer Key
Fusion
Students are encouraged to use the Internet to discover the answers to these
questions. Students’ answers will vary.
EXPLORING SPACE
The Universe: The Vast Reaches of Space
Blackline Master 12—Answer Key
Post-Test
1. What is a light-year?
A light-year is the distance light travels in one year. It is a measurement
of distance.
2. When you look into the night sky you are looking into the past. Explain
this statement.
Distances are so huge in space that it takes years for the light from stars
to reach our eyes. The closest star to Earth other than the sun is 4.3 lightyears away. That means it takes 4.3 years for the light from that star to
reach Earth.
3. How does the sun produce the tremendous amount of energy it releases
every second?
The sun, like other stars, is constantly fusing, or combining, hydrogen
atoms to make helium atoms. This is called nuclear fusion. During this
process a great deal of energy is released.
All rights to print materials cleared for classroom duplication and distribution.
4. What is the solar wind?
The sun constantly releases charged particles in all directions. This is
called the solar wind.
5. Explain why a land-based telescope is not always an effective
observation tool.
A telescope on Earth must look through our atmosphere to view the
stars. The atmosphere is thick with gases and dust, which makes
viewing difficult. Cloud coverage can make viewing impossible.
6. What is a black hole?
Stars that are more than 30 times the mass of the sun can evolve into
what is called a black hole. The star explodes in a supernova explosion
and then falls in on itself. Its gravity is so strong that nothing can escape
it. Everything that comes close is pulled into the black hole. The gravity
is so intense that even light can’t escape.
7. What is the Big Bang theory?
The Big Bang Theory says that about twelve to thirteen billion years ago
all the matter of the universe was contained within an area the size of an
atom. Then this matter began to expand outward.
8. Define the following terms:
a. Nebulae
Nebulae are the gaseous birthplaces of stars.
b. supernova
A supernova is an enormous explosion of elements, gases, and
dust given off by a dying star.
c. galaxy
A galaxy is a collection of stars that are relatively close to one
another.
d. solar system
A solar system is made up of one or more stars with planets,
asteroids, and comets all circling around a central region.
e. Milky Way Galaxy
The Milky Way Galaxy is the galaxy where our sun and solar
system are found. Our solar system is in one of the outer arms
of this spiral galaxy.
All rights to print materials cleared for classroom duplication and distribution.