Project PLATO
Lesson Plan
7-28-99

Group Members:
? Doris Gerhart
? Chantelle Epperly
? Jeanette Dent

Big Science Ideas/ Concepts:
? Scaling is a way for us to deal with the enormous sizes and distances that lie within our solar system by using a comparison to things we know.
? All planets are much smaller than the Sun.

Process Standards
? Systems, order, and organization
? Evidence, models, and explanation
? Change, constancy, and measurement

5-8 Content Standard A (science as inquiry)
? Abilities necessary to do scientific inquiry

Content Standard D (Earth and Space Science)
? The earth in the solar system.

Possible Students Misconceptions:
? The Earth, Sun, and Moon are about the same size.

Measurable Objective:
? The students will estimate relative size.
? The students will calculate scale.
? The students will observe the relative size of the Earth, Moon, and Sun.
? The student will be able to explain that when one object in a scale model changes all objects must change by the same amount.

Materials Required:
? toy cars of various sizes
? balloons
? clay
? rulers
? calculators
? toothpicks
? index cards

Description of lesson:

1. Each group of students will be given a toy vehicle.

2. Students will then be directed to use the stuff in their box to
? Can you make me a person who would drive the vehicle that your group has?

3. Students will discuss and build their people then report their findings to the class. Students should report on why they decided on the size and the class can agree or disagree with each groupís findings.
Class discussion should focus on
? Why are the people different sizes?
? What is this process of making objects smaller called?
? Where do we see scale models other than toys?
? Why do you think we need scale models?

4. Students will be introduced to the mathematical equation for figuring scales.
? (scaled equivalent) = (scale model distance)
(reference distance)   (real distance)
Students will work several sample problems to find the relative size of the Earth and the Moon if the Sunís scale is set.

5. Outside: Students will then be given a balloon and asked
? How does the sun compare to the observatory dome?
? What size do you think Earth would be if our Sun were the size of the dome of the observatory?
? After each student has been given time to blow up their balloons and agree on a size, the students will be given the correct diameter of Earth.
? Students will be asked to correct their balloon sizes by measuring the diameter of their balloons.
? The same procedure will be followed to find the size of the moon.

Possible extension:
? If time allows Studentís will be asked to determine the relative distance that the Earth would be from the Sun, and the relative distance from the Earth that the moon would be.
? Project Astro-Solar System Scale Activity D-5
? Project Astro-Thousand-Yard model (or the Earth as a Peppercorn) Activity D-7

Relevant Internet Sites:
? Interplanetary Hike
www.jetcity.com/~science/planet_activity.html
This is a Stratton House site, which brings home the vast distances of our solar system.  Using a scale where the Earth and Moon are separated by the width of a childís little finger, Mercury Venus, Earth, and Mars would be about one step while reaching Pluto would take 100 more steps.

? San Francisco Exploratorium
www.exploratorium.edu/ronh/solar_system
At this site you choose how big you want your sun to be in your model and then a chart tells you how big to make of the planets and how far away from the Sun they should be.

? NASAís Project Galileo
www.jpl.nasa.gov/galileo/sepo/education/nav/scale.html
At this site the planets are shown in color and to scale.

? Scale in the Solar System
This site consist of a detailed Teacherís Guide, Student Activity sheets, Size Tables, Distance Tables, and extensions which are all correlated to content standards and benchmarks.

End of lesson assessment
? The assessment for this lesson is built in with the questioning strategies used throughout it.
? We could also assess them in writing by asking the following questions:
? Describe what you did today?
? What did you learn about the relationships between the Sun, Earth, and Moon?
? The diameter of the Sun in a scale model of our solar system is 100cm. How big would Earth be?  How does this model compare to our solar system?
? Can you have objects of different scale sizes in the same model? Explain your answer.

Scoring Rubric

3 ñ Student answer is correct and uses scientific terms in
complete thoughts.
2 ñ Student answer is correct and is expressed in complete
thoughts, but student does not use scientific
terms in their explanation.
1 ñ Student answer is unclear, does not express complete thoughts,
and lacks scientific terms.