Student Resource Sheet ESS - 4

UNIVERSAL PICTURES

Looking out the space ship window, you notice a hazy band of light stretching across the sky. “What is that band of stars?” you wonder to yourself. Your STAR advisor tells you that you are looking at some of the stars in a galaxy. As you think about how this information will fit into the book or presentation you will be designing when you complete your trip, you learn that astronomers estimate that there are between 50 billion and 100 billion galaxies composed of groups of stars, gas, and dust clouds which make up the universe. With so many different galaxies out there, you might wonder, “What do they all look like? Are they all the same? How do scientists tell them apart?” In this investigation, you will be comparing different galaxies in order to explain their properties.

Objective

When you have completed this investigation, you should be able to

  1. classify different galaxies in order to describe the characteristics of galaxies.

Materials

print resources

pictures of galaxies

Activity 1: Comparing Galaxies

  1. Observe the galaxy pictures provided by the teacher. Each picture represents a different galaxy.
  1. Classify the galaxy pictures into groups. It is up to you and your group to decide which pictures to group together.
  1. Describe the method your group used to classify the galaxy pictures.

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Activity 2: Gathering Information about Galaxies

  1. Utilize the resources provided to gather information about the three basic types of galaxies.
  2. Complete the graphic organizer, Types of Galaxies, using information from the resources
  3. Review the method you used to classify the galaxy pictures in Activity 1. Determine the accuracy of your classification based on the information you gathered about the three basic types of galaxies.

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Activity 2: Home Sweet Home

7.Read the selection, “Faster than a Speeding Bullet.”

8.Reread the selection and highlight information about light years.

9.Define light year and explain why light years are used in astronomy.

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10.Review the information in Chart 1, “Sample Galaxy Characteristics.”

Chart 1: Sample Galaxy Characteristics

Characteristics / Milky Way / Andromeda / Virgo A / M32
Type of Galaxy / Spiral / Spiral / Elliptical / Elliptical
Diameter
(light years) / 30,000 / 165,000 / 120,000 / 8,000
Estimated number of stars within galaxy / 100 billion / 200 billion / 2.7 trillion / 3 billion
Distance from the Milky Way
(light years) / ------/ 2,900,000 / 60,000,000 / 2,900,000

11.List the galaxies in order from smallest to largest.______

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12.Pictures taken from space of the galaxies Andromeda, Virgo A, and M32 show that Virgo A is the brightest galaxy of the three. Explain why Virgo A would be the brightest galaxy. Use information from the chart to support your response.

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Analysis

  1. Identify the main characteristic that scientists use to classify galaxies. Use information from the investigation to support your response.

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  1. Review the galaxy pictures you classified in Activity 1. Identify the pictures that could represent the Milky Way Galaxy. Support your choices using information from the investigation.

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ESS - 1

Student Resource Sheet ESS - 4

TYPES OF GALAXIES

ESS - 1