Inquiry Activity
The Solar System in Motion
Purpose: The students will be able to …
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Take part in creating a video that will aid in their comprehension of
the seemingly complex movement of the solar system.
Observe the motion of our solar system from both an objective
(making the video) and a subjective (viewing the video) viewpoint.
Observe the relative distances each orbiting planet is from the sun.
Identify the reason that planets appear to move against the backdrop
of the stars.
Standards Addressed:
(Indiana State Standards)
6.2.3 Select tools, such as cameras and tape recorders, for capturing information.
6.3.1 Compare and contrast the size, composition, and surface features of the
planets that comprise the solar system, as well as the objects orbiting them.
Explain that the planets, except Pluto, move around the sun in nearly
circular orbits.
6.3.2 Observe and describe that planets change their position relative to the
background of stars.
6.3.3 Explain that the Earth is one of several planets that orbit the sun, and that
the moon, as well as many artificial satellites and debris, orbit around the
Earth.
Required Materials:
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Portable video camera
Extension Cord (20ft.)
Christmas lights (5-6 sets)
Paint and brushes
Masking Tape
Tape Measure (>40ft)
Internet Access
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2 Pieces of Cardboard (6X6 ft.)
6 Pieces of Cardboard (3X3 ft.)
Individual Light Bulb Socket and
Light
Television Set or some way to show
the created video.
Introduction:
(Background Information)
A solar system consists of a star or system of stars and the objects that orbit its
center of mass, including planets, asteroids, comets, and artificial satellites. Our solar
system is made up of a medium sized star, the Sun, with many different objects that
orbit it. There are nine planets that orbit the sun: Mercury, Venus, Earth, Mars, Jupiter,
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Saturn, Uranus, Neptune, and Pluto. When astronomers refer to distances in the solar
system they generally use Astronomical Units (AU) as their system of measurement.
One astronomical unit is defined as the distance from the center of the Earth to the
center of the Sun. It
turns out that 1AU =
149.6 billion meters, so
the Earth is 1AU or
149.6 billion meters
away from the Sun. As Earth orbits the Sun the distance between the two celestial
bodies is not always the same, because the Earth’s orbital path is not an exact circle. It is
actually an ellipse that is very close to the path of
Planet
Distance from Sun
Mercury
0.4 AU
a perfect circle. It turns out that on average the
Venus
0.7 AU
distance between the Earth and Sun is one
Earth
1.0 AU
Astronomical Unit (1AU). The orbital paths of
Mars
1.5 AU
the other eight planets are also not perfect circles
Jupiter
5.2 AU
(The figure below shows approximately the
Saturn
9.5 AU
difference between a perfectly circular orbit and
Uranus
19.2 AU
the orbit of Pluto which looks most like an
Neptune
30 AU
Pluto
39.4 AU
ellipse). The orbits of the other eight planets are
even closer to a perfectly circular orbit!
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Before Copernicus, astronomers used to believe that the Earth was at the center of
the universe, and everything orbited the Earth, including the Sun, planets, and stars.
This view became known as the geocentric (Earth-centered) model of the Solar System.
The strength of a theory or model
relies in its ability to explain observed
phenomenon. Much of the direct
observation of the sun, stars, and
planets seemed to verify this model
but not all did. As astronomers
observed the movement of the planets
with respect to the background stars,
they noticed a phenomenon they
dubbed “retrograde motion” an
apparent westward motion with
respect to the background stars. As
certain planets moved eastward across
the sky, from one constellation to the
next, over time they would
periodically travel in small circles.
This phenomenon was difficult to explain using the current geocentric model. The
following illustration is the recreation of a picture that shows the apparent movement of
Mars with respect to the constellation Leo. This illustration shows Mar’s normal
eastward movement as well as its retrograde motion as seen from the Earth (Each dot
along the apparent path of motion is the position of Mars as seen from Earth, once every
couple days). Planets appear to move faster around the Earth than constellations or
stars because they are closer to the earth. If you are riding in a car and you look out the
window the closer an object is to the car the faster it will appear to move past you. The
tree off in the distance appears to be moving slower than the hitchhiker alongside the
road (See the diagram below).
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The astronomers of old did not realize that it only appears as
though everything rotates around the earth. What they did not
consider was whether the Earth itself was rotating about its own
axis. This was not obvious to them, and it is not obvious to us
because it does not feel like the Earth is spinning! If you fell
asleep on a merry-go-round and woke up while it was spinning,
you might think that the nearest swing set was spinning around
you. But the person on the swing set would know that you were
the one spinning around. From the Earth we have the perspective
of the person on the merry-go-round. If someone could observe
the Earth at a distance, they would see that the Earth is spinning
around its own axis, just like the person on the swing can observe
that the person on the merry-go-round is simply spinning around.
Because the Earth is rotating about its own axis it appears as though the Sun,
stars, and planets are zooming by us, just like the tree and the hitchhiker appear to
zoom by the moving car. Just like the far off tree which appears to move much slower
than the hitchhiker next to the road, the very far off stars appear to move slower than
the nearby planets. Therefore over time it appears as though the planets are moving
against the back ground of the stars. (Note: this example only goes so far in its explanatory
power because unlike the stationary tree and hitchhiker, the planets and stars are actually
moving. Unlike the straight path of the car, the Earth travels in a circular path. Also the planets
orbit the Sun and stars do not!)
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This phenomenon, that closer objects appear to move faster than objects farther
away, is the effect of something known as parallax. One good way for students to grasp
the concept of parallax is to have them hold their index finger out in front of their nose.
Tell them to open only one eye and look at their finger, and then have them close that
eye and open the other. There finger should appear to be in two different places when
viewed from different eyes (The faster they can close and open their eyes, one at a time,
the better they will see the change in position of their finger). Now tell them to move
their finger far away from their face and try to view it from both separate eyes again.
Ask them what they notice about the apparent change of position of their finger
compared to when it was close to their face (They should notice that the farther their
finger is away from their face, the less it will appear to change position when viewed
from each eye). This analogy still applies to the stars and the planets even though
everything in the universe is in motion; nothing is just sitting out in space. Because the
stars are much farther away from the Earth than the other planets in our solar system
they appear to mover much slower than the planets. They are so far away from the
Earth that they appear not to move at all.
Procedure:
(Time required: 5 separate 40-50 minute class periods)
Preparation: (For the entire activity)
Planet
 Cut out the names of the planets and constellations on
Mercury
page thirteen. (Day 1)
Venus
Earth
 Make copies of the research questions on page eighteen
Mars
for each group of students (Day1)
Jupiter
 Copy page fourteen onto a transparency (Day 2)
Saturn
 Cut out the planets and Sun on pages fifteen. (Day 2)
Uranus
 Cut out cardboard circles for planets (The table to the
Neptune
Pluto
right contains the appropriate radiuses, so each planet is
to scale.) (Day 3)
 Copy page sixteen onto a transparency (Day 4)
 Make copies of the student worksheet on page seventeen (Day 5)
Radius
1.25in.
2.75in.
3in.
1.5in.
2ft. 9.5in.
2ft. 4.25in.
1ft.
11.75in.
0.5in.
Day 1: (Researching information in the computer lab)
1. Explain to the students that they are going to be learning about our Solar System
and the stars surrounding it. Ask students to identify the type of things that
are contained in our Solar System. The solar system is made up of nine
different planets that orbit the Sun which is a star. Within our solar system are
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many moons that orbit the planets, comets, asteroids, and planetoids (asteroids
that are close to the size of Pluto and are farther away from the Sun than Pluto).
2. Either have the students get into groups of two, or assign them groups of two.
3. Tell the students that each group will be assigned a planet or constellation.
Below is a list of research questions each student will have to answer by using
the internet to find out about their planet or constellation (Below is a list of
questions the students will research for different planets and constellations)
Planets:
o
o
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o
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What is the planet made of?
What is the average temperature of the planet?
How far is it away from the sun?
How big is it? (What is the diameter of the planet?)
How much would a hundred pound person weigh on the surface of
the planet? (visit website c. for the answer)
Constellation:
o Draw a picture of the layout of the stars in the constellation
o What is the constellation supposed to be?
o What is one of the stories or myths about the constellations?
o Who came up with this story? (Greeks, Native Americans, etc…)
4. Have the students pick what planet or constellation they will study by drawing a
piece of paper out of a bowl or hat. (A list is provided on page thirteen)
5. Handout the half-page of research questions and websites (page 18) to each
group of students (There is one sheet for groups studying planets and another
for those studying constellations).
6. Direct the students to the following websites that have the information they
need: (These are also provided on the sheet with the research questions)
a. http://www.nineplanets.org/ (Planet Information)
b. http://www.indianchild.com/know_the_planets.htm (Planet
Information)
c. http://www.exploratorium.edu/ronh/weight/index.html Weight on
other planets!
d. http://einstein.stcloudstate.edu/Dome/clicks/constlist.html
(Constellation Pictures and Information)
Day 2: (Activity showing the relative sizes of the planets’ distances from the Sun)
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1. Have each group of students quickly present some of the information they found
about their planet or constellation (Have them answer the appropriate questions
each group was given).
2. Show the Big Dipper in other cultures transparency (page fourteen). First only
show the picture on the top of the transparency. Explain that this is the
constellation we know as the “Big Dipper”. Explain that other cultures
throughout history saw this same set of stars in the sky and saw something
completely different. Ask the students what else they think others throughout
history pictured in their minds when they saw this group of stars (constellation).
After several students have volunteered answers, display the list of cultures and
their ideas about the “Big Dipper”.
3. Discuss the following concepts with the students:
a. Constellations are groups of stars that are outside of our solar system.
b. Our solar system is made up of our star (the Sun), the nine planets that
orbit the sun, the many moons that orbit the planets, comets, asteroids,
and planetoids.
c. Some of the planets are closer to the Sun than the Earth and some are
much farther away (The closer a planet is to the Sun the faster it orbits the
Sun).
d. Astronomers use astronomical units (AU) to measure distances in our
solar system (1AU is the distance from the Earth to the Sun). See the table
in the introduction that lists the other planet’s distances in astronomical
units.
4. Tell the students that they are
going to make a scale model of
the solar system, showing the
relative distance each planet is
from the Sun (You should have
the Sun and planets cut out from
page fifteen). For the scale
model 1ft. will be equal to 1 AU.
Planet
Distance from
Sun
Distance from
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
0.4 ft
0.7 ft
1.0 ft
1.5 ft
5.2 ft
9.5 ft
19.2 ft
30 ft
39.4 ft
5 inches
8 inches
12 inches
18 inches
62 inches
114 inches
230 inches
360 inches
473 inches
5. (Optional:) Use this opportunity
to teach the students how to
convert a measurement from feet
to inches by simply multiplying by twelve, or convert a measurement from
inches to feet by dividing by twelve.
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6. Place the sun on the right side of the chalk board in the front of the room. In
order to place the planets the correct distance from the sun have several students
help hold an extended tape measure against the wall.
7. Have student volunteers place the cut out planets at the appropriate locations on
the wall using tape (see the table above for distances).
Day 3: (Planet and Constellation Art) These will be used in the video
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Planets - Have the students paint the features of
the planets on the pieces of cutout
cardboard (the dimensions are on
page five). On the back of each
planet cutout have the students record
the planet information they found
from the web. For several of the
planets the students will have to write
their information on a piece of paper
because the piece of cardboard is too
small.
Constellations – Using a large piece of cardboard,
have each constellation group make a
representation of their assigned
constellation. Have the students use a
sharpened pencil to poke holes in the
cardboard at each star location in the
constellation (an individual Christmas light
will be placed in each hole). On the front of
the piece of cardboard have the students
paint a representation of the constellation,
and on the back have the students write the
story or myth about the constellation.
Day 4: (Making the video!)
Introduction: All cultures throughout history have been amazed by what they see in
the night sky. Many cultures and individuals have watched the night sky in order
to gain some sort of wisdom from it. Some people have watched the movement of
the stars and the planets in order to try and predict the future, while others just
wanted to understand how the stars and planets move. Numerous individuals
have had many wrong ideas about how the Earth, planets, stars, and Sun move. For
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a long time many people believed that the Sun, planets, and stars revolved around
the Earth. This seems to make sense if you watch the Sun, planets, and stars over
time (Discuss why this seems to be a valid conclusion from simple observations,
see box below). From the surface of the Earth it is hard for us to really know what is
going on unless we can see things from an outside perspective. Because it would be
extremely expensive to take a field trip to space, to get that outside perspective, we
are going to act out the motions of the
? Why might someone believe the Sun,
planets and the stars so that we can
Moon, and stars orbited the Earth?
find out what is really going on!
 The students might give the example of
(While making the video the students
the Sun rising in the east and setting in
are objective observers of the motion of
the west.
the planets in the solar system. When
 Explain that the Moon and stars also
the students watch the video the
“rise” in the east and “set” in the west,
following day, they are observing the
which gives the appearance that they
motion of the planets in the solar
orbit the Earth.
system from the Earth’s subjective
perspective.)
1. Discuss that we now know that the planets orbit the Sun. The planets orbit the Sun
in nearly perfect circles. Show the overhead copied from page sixteen (Pluto’s orbit is
the most unlike a circle, but it’s still pretty close!). Explain that the other planets’
orbits are even closer to a perfect circle than Pluto’s orbit.
2. Setup the classroom as shown in the figure below:
a. Have the students push all of the desks and chairs against one side of the
room (you need a large circular space to do the video).
b. The light bulb (Sun) should be in the center of the room.
c. Each constellation group should be near the outside of the room (close to an
outlet).
d. There would not be enough room to have all nine planets orbiting the sun for
the video so one student from each of the Venus, Mars, and Neptune groups
will be able to take part as a planet in the video. The remainder of the
students who studied a planet will have to join the rest of the students as back
ground stars.
e. You, the teacher, will be in charge of the Earth (the video camera)
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3. Tell the students that for the re-enactment of the solar system, even though they
actually move through space, the stars and constellations will remain stationary
throughout the video because they are so far away from our solar system (lead the
students through the demonstration illustrating the concept of parallax included in the end
of the introduction section on page four) and because the stars do not orbit the Sun.
Also explain that the closer a planet is to the Sun, the faster it travels through space.
Mercury will have to be moving faster than Earth because it is closer to the Sun, and
Mars will be moving slower than the Earth because it is farther away from the Sun.
Pluto will be moving the slowest because it is the farthest planet from the Sun.
4. In order for the re-enactment to flow smoothly here are a couple things everyone
involved should keep in mind:
a. All of the students, except for the three planets should be quiet and should
not move while recording.
b. The planets will not be moving constantly. Each planet will take its own size
step once every “day” (Since Mercury moves the fastest it will take the
biggest step, conversely Pluto will take the shortest step). During the video
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the teacher should callout each time a “day” has passed so the students who
are the planets will know when to step. The teacher (Earth) holding the
spinning camera will also have to take a step once every day in order to
progress throughout its own orbit around the Sun.
c. Each time the camera completes a full rotation; one “day” has passed. The
start of the 1st day should be when the camera is facing the light bulb or Sun.
Consequently, the start of the 2nd day will begin after the camera completes
its first full rotation and is once again facing the Sun.
d. Progression of Movement: The teacher makes one full rotation while
everyone remains still. Once the teacher finishes the first rotation the students
holding the planets and the teacher each take their appropriately sized step.
The teacher makes a second rotation while everyone remains still. Once the
teacher finishes the second rotation, the students holding the three planets are
the teacher take another step along their orbital path. Continue this
progression for up to ten days.
5. Lights (shut them off), camera, action!! (It may take a couple tries to get it right)
Day 5: (Watching the video!)
1. Hand out the worksheet on page seventeen. Have the students answer the
questions on the worksheet while they watch the video. Stop the video at the
appropriate places, giving the students enough time to answer the corresponding
questions.
Assessment:
You may want to use the following suggested questions for further assessment as
part of a quiz or test. The first two questions were taken directly from the classroom
assessment suggestions for the 6th Grade Indiana State Standards.
1. Which of the following statements is true? (Circle the best answer)
A. Earth does not orbit the Sun.
B. Earth is the only planet that orbits the Sun.
C. Earth is one of several planets that orbit the Sun.
D. The Sun is the only planet that orbits Earth.
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2. On April 20, 2002, at 8 p.m., the planet Venus was viewed near the constellation
Taurus. On October 20, 2002 at 8 p.m., Venus was viewed near the constellation
Libra. What accounts for this change in position? (Circle the best answer)
A. The stars orbit the Sun, but the planets do not.
B. The planets orbit the Sun, but the stars do not.
C. The stars orbit Earth, but the planets do not.
D. The planets orbit Earth, but the stars do not.
3. The shape of each planet’s orbit around the Sun is a _______________.
A. Perfect circle
B. Nearly perfect circle
C. Square
D. Nearly perfect square
4. Each culture has the same stories concerning the constellations (True or False).
_____________
5. Constellations are made up of ___________________.
A. Stars outside of our solar system.
B. Stars inside of our solar system.
C. Planets outside of our solar system.
D. Planets inside of our solar system.
Answers: 1. C, 2. B, 3. B, 4. False, and 5. A
Internet Resources:
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( http://www.nineplanets.org/ ) Planet Information
( http://www.indianchild.com/know_the_planets.htm ) Planet Information
( http://www.exploratorium.edu/ronh/weight/index.html ) Weight on
other planets!
( http://einstein.stcloudstate.edu/Dome/clicks/constlist.html ) Constellation
Pictures and Information
( http://www.astro.wisc.edu/~dolan/constellations/java/Apus.html )
Constellation Viewer
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Author: Aaron Debbink
Planet and Constellation
Cutouts
Day1
Planet:
Planet:
Constellation:
Mercury
Uranus
Cancer
Planet:
Planet:
Constellation:
Venus
Neptune
Taurus
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Planet:
Planet:
Constellation:
Earth
Pluto
Draco
Planet:
Constellation:
Constellation:
Mars
Orion
Scorpio
Planet:
Constellation:
Constellation:
Jupiter
Pegasus
Leo
Planet:
Constellation:
Constellation:
Saturn
Ursa Major
Aries
Overhead Master
The Big Dipper
Day 2
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The Big Dipper in Other Cultures (http://www.erin.utoronto.ca/~astro/lesson7.htm)
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Germany: "Grosse Wagen" Big wagon
China: the "Jade Balance of Fate" and/or special chariot for emperor of the
heavens.
Greeks/Homer: a bear and a wagon
First nations people: a bear or a fisher (a carnivorous animal of northern North
America; like a marten)
Basque: two oxen, two thieves, servant housekeeper and master
Arabian: a coffin and mourners
Medieval England: King Arthur's Chariot
British: the Plough
Southern France: Saucepan
Skidi Pawnee Indians: a stretcher on which a sick man was carried
Ancient Maya: a mythological parrot - Seven Macaw
Hindu: Seven Rishis, or Wise men
Micmac Indians of Canada's Maritimes: a bear
19th Century: a symbol of freedom for runaway slaves who "followed the
Drinking Gourd" to the northern states since the Big Dipper is always in the
northern part of the sky.
Irish: King David's Chariot.
Planet and Sun Cutouts
Day 2
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Overhead Master
Orbit of Pluto
Page 16
Day 3
The Solar System in Motion
Student Worksheet
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Watching the Video, Day 5
Name:________________________________
1. In the video, how do you know when one day passes?
2. What constellation is Neptune closest to on day one?
3. What constellation is Venus closest to on day one?
4. What constellation is Neptune closest to on day six?
5. What constellation is Venus closest to on day six?
6. Do the planets stay in the same place in the sky, when compared to the
constellations or stars, or do they move? Explain why!
7. Which planet appears to move the fastest (Venus, Mars, or Neptune)?
8. Based on your answer above, which planet would appear to move the fastest
around the Sun, Jupiter or Pluto?
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Planet Research Questions
Student Worksheet
Period #_________
Names:___________________________
___________________________
Directions: (Visit the following websites to find answers to the questions, and record
your answers in your science journals)
1.
2.
3.
4.
5.
What is the planet made of?
What is the average temperature of the planet?
How far is it away from the sun?
How big is it? (What is the diameter of the planet?)
How much would a hundred pound person weigh on the surface of the planet?
(visit website c. for the answer)
a.
b.
c.
d.
http://www.nineplanets.org/ (Planet Information)
http://www.indianchild.com/know_the_planets.htm (Planet Information)
http://www.exploratorium.edu/ronh/weight/index.html Weight on other planets!
http://einstein.stcloudstate.edu/Dome/clicks/constlist.html (Constellation Pictures and
Information)
Constellation Research Questions
Student Worksheet
Period #_________
Names:___________________________
___________________________
Directions: (Visit the following websites to find answers to the questions, and record
your answers in your science journals)
1.
2.
3.
4.
Draw a picture of the layout of the stars in the constellation
What is the constellation supposed to be?
What is one of the stories or myths about the constellations?
Who came up with this story? (Greeks, Native Americans, etc…)
e.
f.
g.
h.
http://www.nineplanets.org/ (Planet Information)
http://www.indianchild.com/know_the_planets.htm (Planet Information)
http://www.exploratorium.edu/ronh/weight/index.html Weight on other planets!
http://einstein.stcloudstate.edu/Dome/clicks/constlist.html (Constellation Pictures and
Information)
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