Subject Area(S) Physical Science, Chemistry, Physics and Engineering

Drexel-SDP GK-12 ACTIVITY

Activity : Solar System in a Box-Exploring Length Scales, Large Numbers and Our Nearest Neighbors

Subject Area(s) Physical Science, Chemistry, Physics and Engineering

Associated Unit Astronomy

Associated Lesson Astronomical Distance.pdf

Activity Title Scale Model of the Solar System

Header

Grade Level _7-_8 (__-__)

Time Required 50 min period

Group Size 10 groups of 2

Expendable Cost per Group

Cost of clay per group is $ 4.00

Summary

Students will explore distances in our solar system by making a scale model.

Engineering Connection

Scientists and engineers use models to better understand the real world. They are best known

as representatives for physical objects, but they also help to conceptualize phenomena, systems, processes and abstractions. By physically manipulating models scientists and engineers gain a deeper understanding of the things they are studying. Models can be physical, like ball and stick molecules, or mathematical. The key to using models is understanding that no matter how useful the model is it is only approximating the real system, so there are always flaws.

Keywords

Solar system, models, astronomical unit, light year

Educational Standards

· Science: 3.4.7 D

· Math: 2.3.8.G

Pre-Requisite Knowledge

Students are expected to know how to multiply.

Learning Objectives

After this lesson, students should be able to:

· Convert from inches to centimeters

· Calculate the distance in kilometers, of a planet to the sun, if given the AU.

· Create a spreadsheet in Excel to calculate astronomical distances

· Establish a scale based on the earth’s diameter and calculate the appropriate distances to create a scale model of the solar system

· Build a scale model of the solar system that fits in a 2 meter box.

Materials List

Each group needs:

1. Colored modeling clay

2. Metric/English ruler

3. Calculator or computer

To share with the entire class:

· none

Introduction / Motivation

Large numbers are a difficult abstraction. Most posters and classroom models illustrate the solar system in such a way that the distances between the planets and the relative size of the planets are inaccurate. This is necessary because the planets are small compared to the distances between the planets and for convenience the models are inaccurate.

The students will discover for themselves that it is not possible to build a model that satisfies the design criteria of building a scale model of the solar system in a 2 meter box, in fact it will not fit in the average classroom. They will have to use two different scales, one for the planets and one for the distances between the planets to meet the 2 meter box requirement.

Vocabulary / Definitions

Word / Definition
Astronomical Unit (AU) / The average distance from the earth to the sun. 149,597,870.691 kilometers. The AU is used to measure distances in our solar system.
Light Year (LY) / The distance light travels in one year. There are 9.4605284 x 1015 meters in 1 light year.
Speed of light / 2.99792458 x 108 meters/sec

Procedure

Background

See attached pdf of a PowerPoint presentation. Astronomical Distances

Before the Activity

Show the student the presentation defining the terms for this activity. Pass out the activity work sheets. Go through how to set up an Excel spread sheet, some students may not know how to enter a formula and fill down. Also after selecting an example scale demonstrate with a meter stick or ruler how to translate the lengths from the calculations to the ruler. For example: What does 1.5 cm measure on a ruler? Demonstrate also how to estimate the diameter of a sphere on a ruler.

With the Students

1. Explain how to calculate the conversions. Go through the examples on the work sheet. Ask them to do the next problem themselves. Walk around the classroom and answer questions.

2. Have them open Excel and create a spreadsheet to do the same calculations.

3. The students should then decide on a scale (ie 1 cm = 1 earth diameter) and make scale models of the planets. It is instructive to try several scales before deciding on the best fit for their model.

4. Let them figure out they cannot use the same scale for the distances between the planets.

Attachments

Astronomical Distances PDF

Astronomical Distances worksheet.doc

Safety Issues

Use non toxic clay.

Troubleshooting Tips

none

Investigating Questions

1. Explain how you determined the scale for your model? What were the design constraints?

2. Were you able to use the same scale for the size of the planets as you used for the distances between the planets?

3. Did you have enough material to include the Sun? Explain your answer using some of the calculations you did?

4. What surprised you the most when making the model?

Assessment

Pre-Activity Assessment

none

Activity Embedded Assessment

Check each group’s models. Ask

Post-Activity Assessment

none

Activity Extensions

http://www.nasa.gov/topics/solarsystem/index.html

Ask the students to keep a journal of the night sky. Identify the planets and constellations.

Additional Multimedia Support

References

See attachment.

Other

Redirect URL

http://www.ioncmaste.ca/homepage/resources/web_resources/CSA_Astro9/files/html/module4/module4.html

Owner

Drexel University GK-12 Program

Contributors

Jennifer Atchison, Dorothea Stanley