National Aeronautics and Space Administration

Educators' Corner

Activity #2 - Identifying Galaxies

In this activity, students describe the characteristics of the different types of galaxies (spiral, elliptical, barred spiral, peculiar, or irregular) in their own words. They also classify galaxies seen in the Hubble Deep Field. Note that this activity uses the transparencies that accompany this booklet. The transparencies are also available at http://imagine.gsfc.nasa.gov/educators/galaxies/transparencies/

See Student Worksheet

Worksheet Answers/Assessment Guide

1. Show the students either "The Hidden Lives of Galaxies" poster or Transparency #1: Types of Galaxies. Students write a brief description of each galaxy type. Titles will vary, but may be, e.g. "The Galaxy Types", or "Five Types of Galaxies".
   1. Spiral - galaxy with tightly wound spiral arms
   2. Elliptical - slightly elliptical to nearly circular
   3. Barred Spiral - spiral with a bright bar of gas through the center
   4. Peculiar - fits none of the descriptions
   5. Irregular - small, patchy, irregularly shaped galaxy
2. Show Transparency #2: Deep Survey Image. Students identify the types of the ten galaxies labeled on the Deep Survey Image.
   

   Irregular Spiral Spiral Elliptical Barred spiral

   Barred spiral Elliptical Spiral Irregular (or Peculiar) Elliptical

Assessment
Inferences that can be made from observing the Hubble Deep Survey Image should include that the objects are galaxies and not stars. These galaxies are of different sizes, shapes, brightnesses, distances, and color.