Stimulating Understanding of Computational science through Collaboration, Exploration, Experiment, and Discovery for students with Hearing Impairments
a collaboration of the Shodor Education Foundation, Inc., Eastern North Carolina School for the Deaf, Barton College, the National Technical Institute for the Deaf, and Interpreters, Inc.

For Teachers!

Predicting Lunar Eclipses

Overview:

In this lesson the students explore one of the regularities in nature, namely lunar eclipses. They discover how to predict eclipses the same way ancient people did. They look at dates of recorded eclipses and find a pattern. They put their pattern into a spreadsheet and check to see if their algorithm works. As is often true in life, the first attempt doesn't work because we don't have enough data to see the true pattern. They are able to find the pattern when they are supplied with the eclipse dates that fall in a Saros cycle.

As an extension you can have the students search for other eclipse cycles by building another spreadsheet. This spreadsheet predicts new moons, and also when the moon passes through the plane of the sun/earth. By looking at these dates they can predict eclipses and find cycles.

Goals and objectives: 

1) The students will discover that patterns and regularities can be found in astronomical phenomena. 
2) They will discover the Saros Cycle that allows us to predict both lunar and solar eclipses. 
3) They will learn the orbital mechanics behind the Saros Cycle. 
4) Students will learn that the modeling process isn't finished with the first try. We need to check our model against our observations to see if its predictions are accurate. Our models are frequently refined to improve their accuracy.

Student Prerequisites: 

Students need to be familiar with spreadsheet construction: formatting cells, copying cells, putting formulas in cells.   

Materials Needed: 

Worksheet: Table with twentieth century lunar eclipses. 

Computers with spreadsheets and Internet access or CD with this lesson.

Developed by
The Shodor Education Foundation, Inc.

Copyright © 1999-2001 by The Shodor Education Foundation, Inc.

This project is supported, in part, by the National Science Foundation Opinions expressed are those of the authors and not necessarily those of the National Science Foundation.