Learning Exercise

Understanding and Creating My Own Galactic Classification System

A student workgroup will create, compare and contrast a Galactic Classification system to one that was developed by Edwin Hubble.

This activity may be used as a stand alone or as additional supplement to the materials found on this website.
Course: Earth Science, Astronomy

Student tutorial page relating to the Hubble's classification scheme of galaxies. Includes student worksheet (see... see more



1. Provide handouts to students which enable them to detail their own
classification system for the types of galaxies.

2. Upon examining the different characteristics of the galaxies, the students
will devise their own classification system.

3. After this, the student group will review the scheme developed by Edwin
Hubble and record the previously viewed photos in their appropriate categories.

4, Next, the student group will compare the two categories.

5. The student group will then answer the inquiry based "Lesson Debriefing",
critical thinking questions.


1. After receiving your two handouts titled Activity 1 and 2, review the
galactic classification system found under the title, "Scientific Background",
at URL http://btc.montana.edu/Ceres/html/Galaxy/gal1.html#lessonplans.

2. Next, based on your review and using the Activity 1 worksheet, devise your
own cataloging scheme based on the physical characteristics found in the photos
found in "Scientific Background".

3. For Activity 2, again look at the photo set and use the system developed by
Edwin Hubble.

4. Compare the two schemes by discussing them with your group the advantages and
disadvantages of them both.

5. As a group, answer the "Lesson Debriefing" questions on separate paper, with
your responses, to your instructor.

6. Each of you in the group will open up the URL
http://smv.org/hastings/student2.htm#colors. Review the concepts, then take the
Classifying Galaxies Quiz.

7. Discuss your individual results with your team members.


Student should have a prior-knowledge of the solar system recognizing that beyond the Milky Way are other galaxies, perhaps similar or disimilar to our own. Students should also be familiar with the concept of astronomical units (AU) as the measurement for distances between galaxies.


Topic Covered: Galaxy Identification, sub-grouping, cataloging, and classification. Inquiry based assessment.

Type of Task

Learning Objectives

Recognize that galaxies are collections of billions of stars.
Understand that galaxies take a variety of forms.
Develop and apply a galactic classification scheme.
Comprehend that galaxies are classified in four major categories.