Teacher's Page Classifying Galaxies:
A lesson on how Galaxies are classified by shape.

Lesson Plan Content

TABLE OF CONTENTS:

• Purpose
• Student Objectives
• Procedure
• Assessment
• Ties to Science Framework
• Related Lessons

Return to Lesson Summary - Main Page

The purpose of this lesson is twofold:

2) You will practice the technique, useful in science, of engaging a scheme or plan to classify objects in a group. In this lesson you will be able to look at images of different kinds of galaxies, taken by the world's best telescopes. In most high school astronomy texts and in some earth science texts, the Hubble Tuning Fork Diagram is presented as a way to classify, or put into groups, the various types of galaxies observed in space.

If you are not studying galaxies, this lesson still might be useful. It follows, in an organized way, the process by which scientists group or classify objects in nature. The lesson is designed to be used either way.

Return to the Table of Contents

Student Objectives

Students will :

1- Examine pictures of galaxies.

2- Discover that these pictures have been arranged according to a scheme or plan laid out by Edwin Hubble in the 1920's.

3- Practice using the scheme, called the Hubble Tuning Fork Diagram, to classify unidentified galaxies, as presented in pictures.

4- Display the knowledge gained during this activity using a worksheet presented by the teacher.

5- Demonstrate an understanding of what "classification" means as it relates to science.

6- Examine an unidentified galaxy image and attempt to classify it based on the methods that they have learned.

Return to the Table of Contents

Procedure

Teacher Component

In any study of "the Universe", the subject of galaxies normally will be covered by the teacher. If the teacher decides to go into more detail, and to present the idea of different types of galaxies that exist in the universe, this activity would be an excellent follow-up to an initial teacher introduction. We see this activity as a group workstation activity involving one group or many groups. It could be used as an extension of a classroom presentation. It also could be used as a review, if the Hubble Tuning Fork Diagram is covered by the teacher.

It has been designed so that just two main ideas are presented:

1) the scheme of Edwin Hubble's Tuning Fork Diagram.

2) practice in using his scheme as an example of how scientists attempt to classify objects in nature.

Students will begin the lesson at the blinking message: "Start your galaxy exploration here". Students will indicate their mastery of the objectives by responding to questions on a paper worksheet. The worksheet should be copied and printed, and handed to students to complete as they participate in the activity. A worksheet you may use is provided at the end of this section, followed by a copy of the worksheet with answers (Teacher Key) for your use.

One way to print the student worksheet for this lesson is to click on "File" at the top of your web-browser screen, and select "Print" if your computer has a printer available. If you do not have a printer accessible from your browser, you can click on "File", and select "Save as" to save the worksheet to a floppy disk. You can then use the file in a word processor.

There are many fascinating links to this subject that we have found. We would particularly like to recommend this one:  "Cosmic Classifier", one of four astronomy activities at the "Hubble Deep Field Academy".    We mention it in the student activity specifically as an option, but you should take a look at it.  You may want to assign it as well. We think it is a perfect extension and follow-up of our simple activity. It is not particularly difficult, and would be appropriate for upper elementary or middle school students.   NOTE:   The "Cosmic Classifier" activity will require your computer to be able to use Adobe Acrobat Reader, which is available for free download at the site.

There are other excellent links which are noted and described under "Extensions" in the Table of Contents.

Student Component

Students will begin the lesson at the blinking message: "Start your galaxy exploration here". Students will indicate their mastery of the objectives by responding to questions on a paper worksheet.

Get Student Worksheet

Get Worksheet Answer Key

Go to Student Lesson

Return to the Table of Contents

---

Lesson Plan Assessment

1. Students will mark their progress by answering questions on a worksheet . This worksheet is provided online for teachers to copy. Teachers may also copy an answer key, also provided online, to check on students' progress.

2. Students will use an ONLINE activity to classify galaxies by placing images of galaxies on the Hubble Tuning Fork diagram, using the classification scheme developed by Edwin Hubble.

3.  Students will examine an unidentified galaxy image, and attempt to classify it based on the methods that they have learned.

Return to the Table of Contents

Lesson Plan Ties To Science Framework

Link to Science Standards of Learning for Virginia

Project 2061:    Benchmarks for Science Literacy:    Recommendations of what all students should know and be able to do in science, mathematics, and technology by the time they graduate from high school.

This nationwide study is one of the major frameworks and we include specific references from that study below for grades 5-9:

• The universe contains many billions of galaxies, and each galaxy contains many billions of stars.

• Increasingly sophisticated technology is used to learn about the universe. Visual, radio, and x-ray telescopes collect information; mathematical models are used in studying evidence from many sources in order to form a scientific account of the universe.
• Scientists try to observe as wide a range of natural occurrences as possible to be able to discern patterns.
• Tables, graphs, and diagrams can show how values and/or objects of one type are related to values and/or objects of another.
• Some aspects of reasoning have fairly rigid rules for what makes sense; other aspects don't. If people have rules that always hold, and good information about a particular situation, then logic can help them to figure out what is true about it. This kind of  logic requires care in the use of key words such as if, and, not, or, all and some. For example, people are using incorrect logic when they make a statement such as "If A is true, then B is true; but A isn't true, therefore B isn't true either".
• Sometimes people invent a general rule to explain how something works by summarizing observations.
• All scientific investigations usually involve the collection of relevant evidence, the use of  logical reasoning, and the application of imagination in devising hypotheses and explanations to make sense of the collected evidence .

Return to the Table of Contents

---

Lesson Plan References

• Pasachoff, Jay M. "Journey Through The Universe, 1994 Version". 1992. Sanders College Publishing. Harcourt Brace Jovanovich. New York.
• Sandage, Allan.  "The Hubble Atlas of Galaxies". 1961. Carnegie Institution of Washington. Washington, D.C.

Return to the Table of Contents

---

Related Lesson Plans

Hubble Deep Field Academy:  Four activities related to galaxy astronomy:

1- Stellar Statistician: uses the Hubble Deep Field Image in an exercise to teach about sampling.

2- Cosmic Classifiers:  a very visually appealing activity with more complicated galaxy identification involving color, size and shape.

3- Galactic Guide: an activity on determining the distances to galaxies.

4- Universal Graduate: a review quiz on concepts presented in the four lessons above.

Sky Den - an excellent site with basic lessons and multiple links on these topics:

1.Our Solar System

2.Galaxies

3.Clusters, and Beyond...

4.Gravity

5.The Expanding Universe

6.The Big Bang

7.The Fate of Our Universe

8.Weighing the Universe

9.Formation of a Galaxy

10.The Doppler Effect

Return to the Table of Contents

Return to Lesson Summary - Main Page

Go to Student Lesson

---

SEGway	This lesson was developed by George & Jane Hastings  in collaboration with the  Science Museum of Virginia
Send comments or questions to George & Jane Hastings or outreach@ssl.berkeley.edu
Copyright © 1996, 2001 The Regents of the University of California

 

This page last updated July 26, 2001