Download honey, i shrunk the solar system

“HONEY, I SHRUNK THE SOLAR SYSTEM”
MODIFIED VERSION OF A SOLAR SYSTEM SCALE MODEL ACTIVITY FROM
UNDERSTANDING SCIENCE LESSONS
OVERVIEW
Students will construct a scale model of the solar system using a fitness ball to represent the
sun. They will calculate the appropriate diameter of the scale model planets and their distances
from the sun. They will then make models of the planets out of clay and set up the model over a
distance of approximately 1.7 km (not including Pluto) or 2.2 km (if including Pluto).
If you do not have 1.7 km to walk with your students, there are two alternatives:
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Measure the longest distance they can use on the school grounds and use this to set
their scale for planetary distances. You will then need to use a different scale for the
planets' sizes.
Students can walk the distance of Saturn (0.5 km or 0.3 mile). Use a large picture of the
school and area from Google maps satellite view and mark the points where each outer
planet would go.
Grade span: 6-8
OBJECTIVES
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The students will be introduced to parallax and how it can be used to find planetary
distances.
Determine the distance to the object by sighting a distant object from 2 different
locations and knowing the distance between those locations.
Create a scale model of our solar system that includes distance from the Sun and the
diameter of the planets.
Use ratio and proportion to compare the size of the scale model solar system to the
actual size of our solar system.
Describe the parts of our solar system in terms of size, distance, and location.
Match appropriate units with given situations and convert units within a system of
measurement (kilometers and Astronomical Units).
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
MATERIALS
For the Teacher:
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Dry Erase Markers, or Viscam Camera
Masking Tape
Fitness ball ( 53 cm in diameter )
For Each Group:
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Planetary Data Sheet
Graph paper
Activity Page
Pencils
Ruler
Measuring Tape
Protractor
Air-Dry Clay
Calculator
Index Cards
Toothpicks
Time: Part I – 30 min; Part II – 60 min; Part III – 30 min
TEACHER BACKGROUND ON THE SOLAR SYSTEM
Our solar system consists of a star, our sun, and 8 planets. Pluto was considered a planet until
2006 when the International Astronomical Union reclassified it as a "dwarf planet". For the
purposes of this activity, we've included Pluto, but you can refer to it as a dwarf planet. The
planets are (in order, from the Sun, outward): Mercury, Venus, Earth, Mars, Jupiter, Saturn,
Uranus, and Neptune. A new mnemonic used to remember the planets in order is, "My Very
Educated Mother Just Served Us Nachos."
The solar system consists of eight planets orbiting around one star: the Sun. Neptune, the
farthest planet from the Sun, orbits at approximately 30 astronomical units (AU) from the Sun.
An astronomical unit is a unit of length used by astronomers. One astronomical unit equals the
average distance from Earth to the Sun — about 93 million miles (150 million km). The solar
system also includes the Kuiper Belt, a comet-rich area that begins near Neptune's orbit and
stretches far beyond it, to about 50 AU from the Sun. Part of Pluto's elliptical orbit extends far
into the Kuiper Belt. Beyond Pluto's orbit is another region of icy objects in our solar system,
called the Oort Cloud, which extends approximately 50,000 AU from the Sun. In addition, there
is an asteroid belt that lies in the zone between the orbits of Mars and Jupiter.
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
PART I PROCEDURE: PARALLAX METHOD
1. Place the fitness ball in the middle row on the front desk just at eye level for your
students while seated. Place an X mark on the board directly in front of the fitness ball
also at eye level. Any students sitting in the same row as the fitness ball should be able
to see the ball but not the X.
2. Ask the student in the back of the row furthest right to describe how they see the ball in
relation to the X. They should say something like “the ball is on the left and the X is on
the right”. Make a quick sketch on the board. Ask the student at the back of the middle
row and the student at the back of the row furthest left to also describe what they see.
Make a quick sketch of both of their views.
3. Explain that scientists describe this apparent shift as a “parallax shift” or just “parallax”
for short. We often experience this in everyday life. Move the ball out of the way and
have each student close their left eye, extend one arm, and cover the X mark with their
thumb. Once the X is covered have the students open the left eye and close the right.
The thumb will appear to move back and forth due to parallax. Parallax allows the brain
to see two slightly different images (one from each eye) and combine them to produce a
3D image.
4. When astronomers measure the parallax of an object and know the separation between
the two positions from which it is observed, they can calculate the distance to the
object. Using observations on Earth separated by thousands of miles -- like looking
through two eyes that are very far apart -- parallax measurements can reveal the great
distances to planets.
5. Place the ball on the front desk. Ask the students to determine the distance to the ball.
Mark two places, A and B, for instance by using masking tape. The points A and B,
together with the ball at point C, form a triangle. Ask the students to measure the
distance AB with the tape measure.
6. Ask the student to stand at point A and measure angle BAC, and then move to point B
and measure angle ABC.
7. Then ask the students to draw a scale model of their measurements. The students will
use their ruler and the scale, to calculate the distance from the baseline to the ball.
8. Ask students to compare the actual distance and the distance determined in Step 7.
Discuss some possible sources of error.
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
PART II PROCEDURE: CLAY MODEL
1. Ask students "Why do we build models?" to generate discussion of models.
2. Then ask the students to name the planets on our solar system. Write the names up on
the board in the correct order from the sun. Ask them how big the planets are and how
far away they are. After some struggle with this, offer up the solution of building a
model to help.
3. Show them the fitness ball and ask them how big each of the planets would be if the sun
was the size of the fitness ball. Ask for a few volunteers to come up to the board and
draw and label each of the planets compared to the fitness ball.
4. When this drawing of the solar system is complete, ask students how far apart each of
these planets would be if the sun were a fitness ball. Would they fit in this room? Would
they fit in the school? Write up some of their guesses about the size of the solar system
on the board and make sure you can keep the answers there until the activity is
completed.
5. The class needs to figure out what their scaling factor will be for the solar system if the
fitness ball is going to represent the sun. Explain that you will need to measure the
fitness ball and compare it to the real diameter of the sun. Then you can determine how
many km each cm of the fitness ball represents. Ask for a couple of volunteers to
measure the fitness ball.
6. Show students the measurements in the Planet Data Sheet table in the "Materials"
section. Do the scaling factor calculation by dividing the actual diameter of the sun by
the diameter of the fitness ball. Explain that the answer represents the number of km in
every cm of your model.
7. Explain that we will use this scaling factor to figure out the sizes and distance from the
sun of all the planets in our model. Demonstrate how to use the scaling factor to
determine the diameter and distance from the sun of a hypothetical planet (so that you
leave the real planets for the students.
8. Pass out clay, index cards, and ruler to each group. Instruct them to label the 8 index
cards with the names of the 8 planets and to make a model of their planets with the
correct diameter out of the clay.
9. When all the planets are represented, have the whole class take a look at their model.
Refer back to their drawings on the board from Step 2. Ask the class, "What can we
learn from this model?” Take this opportunity to discuss the value of models in science.
NOTE: If you are unable to walk the distances of this model solar system or to use
Google maps to place them on a map, you can stop here and simply make these clay
models into a mobile or other permanent display.
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
PART III PROCEDURE: PLANETARY DISTANCES
1. After this brief discussion, announce that you need to complete the model by placing
the planets at the correct distances from the sun. Ask students to give you the model
distances they calculated. They will be in AU, which will be difficult for students to
imagine. Take Mercury as an example and convert it into something the students will
have a better feel for, like feet or meters. Ask students how far away this distance is. In
the classroom? Outside? If outside, where? How far from the classroom?
2. Have the students count how many paces it takes for them to walk a distance of 2
meters on a marked practice area. You can then tell them the multiplying factor to reach
Mercury and do this for each planet. For example, if Mercury is going to be 22 meters
away and they measured their pace for 2 meters, they will need to multiply their pace
by 11 to find how many paces to take.
3. The total distance of the model will be roughly 1.7km, so you need a wide, open space
you can walk this distance and leave the clay planets. Have the student count their
paces from the start (where you've left the fitness ball sun) to each planet. At Mercury's
distance you'll leave the planet on the toothpick and continue to the next planet.
Continue from there, leaving each clay planet at its appropriate distance.
4. When you reach the end, have students look back and try to see the sun and each
planet. Have a parent volunteer or teaching assistant stay at each place and then hold
up the sun and each planet so that everyone can get a good look at the model. They will
not be able to see most of the planets. You can add in that if we included Pluto, it would
be 2.2km away from the sun.
5. Return to the classroom, take a second look at the distances from Step 4 in Part II. Ask
students again what they learned from this model. Point out again that models are
useful in this way in science. Sometimes scientists construct scale models to:
— study particular aspects of a complex system
— build a basic understanding of a system
— narrow one's focus and/or eliminate possibilities
— gain a more intuitive understanding of a system
— figure out what questions to ask about a complex system or problem
— help us visualize systems that are too large or too small to see
Reflection: Ask students to reflect on this activity and the use of models in science:
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How did building the model of the solar system change the way they visualize the solar
system?
What additions or changes would they make to the model if they could do it again?
What other models have they seen or used?
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
PLANET DATA SHEET – INNER PLANETS
Planet
Distance from
Sun km
Mercury
58,000,000 km
Venus
Earth
Mars
108,000,000 km
150,000,000 km
228,000,000 km
12,104 km
12,755 km
6,790 km
Distance from
Sun in AU
Scale Distance
in cm
Diameter in km
4,878 km
Scale Diameter
in cm
Avg. Surface
Temperature
662
869
59
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
-9.4
PLANET DATA SHEET – OUTER PLANETS
Planet
Distance
from
Sun km
Jupiter
Saturn
Uranus
Neptune
Pluto
778,000,000 km
1,429,000,000 km
2,875,000,000 km
4,504,000,000 km
5,900,000,000 km
142,796 km
120,660 km
51,118 km
49,528 km
2,300 km
Distance
from Sun in
AU
Scale
Distance in
cm
Diameter in
km
Scale
Diameter in
cm
Avg. Surface
Temp.
-238
-292
-366
-391
In August 2006, Pluto was reclassified as a “dwarf planet”.
Tanya Huffman, M.A., Mathematics Instructor II at Florida Gulf Coast University
Office Library 464 – K
(239) 590 – 7648 [email protected]
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