National Aeronautics and Space Administration

Activity #3
Classifying Galaxies with Hubble's Fork Diagram

Part I
Brainstorm answers to the following questions in your group.

1. Why do people put things into classifications or categories? How does this help us?
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2. What are some things we categorize in our daily lives? Why?
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3. What types of objects do scientists classify? Name five different areas of science that classify objects and identify them. Tell what they classify.
   

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Part II
In your groups, look at the images of actual galaxies and suggest answers to the following questions.

1. Pretend that a NASA astronomer comes to your school and asks you to name the galaxies pictured in the chart based upon their resemblance to common objects. What would you name them? Write your suggestions underneath each picture.

   

2. Without using any prior information, how many different types of galaxies are represented in these pictures? Decide on how many groups or classifications you would have and give each group a name. Then, underneath, include the criteria you would use to include a galaxy in this group.

   • Group Name : _______________________________________
     Criteria : __________________________________________
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   • Group Name : _______________________________________
     Criteria : __________________________________________
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     Criteria : __________________________________________
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3. Now imagine that the NASA astronomer needs your help to classify these newly discovered galaxies based upon your knowledge of the Hubble Fork Diagram. Classify each galaxy according to that scheme. Write the galaxy type and classification below your name of each image. (For example, the Andromeda Galaxy is Spiral, Sb.)

Part III - Optional

In your groups, research one of the different types of galaxies in the Hubble Fork Diagram. Using the resources provided by your teacher, identify the following information about your galaxy type and present this information to the class.

• Type and classification
  
• Shape
  
• Examples of this galaxy type
  
• How this galaxy forms
  
• How stars move in this galaxy type
  

You must use at least one of the following methods to present this information: create one large 3-D poster, write and perform a skit, write and perform a song or rap, or create a 3-D model.