deep space



Did you know there are around 100 million galaxies in our observable Universe? With new telescope technology helping to generate more images of these galaxies than could ever be seen and understood by astronomers, a creative solution was needed. You might think, why can’t a computer to do it? Sounds good, but it turns out people are way better than computers analyzing these types of images and it is actually really fun to see pictures of our Universe that have never been seen before! Join Galaxy Zoo and work with astronomers to study galaxies, understand how galaxies around us formed and what their stories can tell us about the past, present and future of our Universe.

Description                                      Content Standards

Why is this Important?                  NGSS: Science Practices

Put things in Perspective                NGSS: Crosscutting Concepts

Crowdsourced Space Out!             Common Core: English Language Arts

Observe Galaxies                           Common Core: Mathematics

Classify Galaxies!

Analyze Data

Extend Your Experience    



Join a community of over one million online citizen scientists working with astronomers to understand galaxy formation by classifying galaxies according to their shapes and characteristics.


  • Computer with internet access

  • Other materials as detailed within individual activities


Activity 1: Why is this Important?

With big advances in telescope and satellite technology, astronomers deal with lots of pictures. Over one million galaxies that have been imaged by the Sloan Digital Sky Survey alone! And that isn’t the only set of images. They realized that even if all the astronomers in the world only classified galaxies for the rest of their lives it would still take 200 years to complete the work, so they created the Galaxy Zoo project and invited the public to help. Within 24 hours, they were receiving 70,000 classifications per hour; by the end of the first year, more than 50 million classifications were made by 150,000 people. That meant each galaxy was seen by many different participants, which helped ensure the classifications were reliable, accurate, and just as trustworthy as those made by professional astronomers.

To help your students understand why astronomers need help classifying the galaxies here are two exercises you can do.

Exercise 1: Listen to an interview from 2011 with astronomer Dr. Kevin Schawinski, one of the co-founders of Galaxy Zoo.

Exercise 2: Read these two articles and have your students consider these questions as you read. What questions do you have about galaxies? What questions are the astronomers involved in Galaxy Zoo asking?

It works! And is even more successful than they could have imagined. Citizen scientists not only correctly identified the shapes and features of the galaxies, but also discovered brand-new astronomical objects and brought to light a whole new class of galaxy. These remarkable achievements could not have been made without this tremendous response from the people all over the world, just like you.

Activity 2: Put things into Perspective

How big is the observable Universe? How far away is the nearest Milky Way Galaxy neighbor? How far can these telescopes really see?

The following exercises will help your students start to think about how amazing it is that we can see these galaxies at all!

Exercise 1: When talking about the observable Universe astronomers start to use very large numbers. Have your student watch TED ED Powers of 10 video to become familiar large numbers and scientific notation.

Exercise 2: Although understanding distance is not the main point of this activity, you will want to be sure students are mentally placing galaxy images outside the Milky Way. You can do this through the use of a variety of web resources such as:

Exercise 3: How far away are the galaxies?

  1. Remind students of the enormous distances between Earth and the nearest galaxy.
  2. Place two dots on the board, one centimeter apart. If this represents the distance between Earth and the edge of the Milky Way (approximately 40,000 light years), then the Andromeda Galaxy (2.5 million light years) would need to be placed 62.5 centimeters away. Andromeda is 62.5 times the distance between Earth and the edge of the Milky Way.
  3. You may want to take this a step further: If you make the one centimeter distance between the two dots represent the 93,000,000 miles (eight light minutes it takes light) to travel from the sun to Earth, then one light year would be approximately 657 meters away or (365 x 24 x 60) / 8. Earth is approximately 40,000 light years away from the edge of the Milky Way. At this scale, we would need to place the dot representing the edge of the Milky Way 26,280 kilometers away (657 m/ly x 40,000 ly) and Andromeda would be placed 62.5 times further still. [Helpful hint: Find landmarks or known areas that are located 26,280 km and 1,642,500 km from your school, respectively. This will allow your students to have a better understanding of these large numbers.]
Activity 3: Crowdsourced Space Out! Or two (or more) heads are better than one.

We can often get to the best answer more quickly and easily by bringing many eyes and perspectives to help solve problems. Different interpretations of the same data exist and crowdsourcing can help mitigate the influence of outliers and at the same time lead to interesting discoveries. Galaxy Zoo and many other Citizen Science projects use crowdsourcing as a tool.

Below are different exercise to allow your students to see for themselves how crowdsourcing is beneficial for scientists.

Exercise 1:

  1. Divide into four or five teams of two-five people. Each team will use a different source to answer these questions about galaxies. Write down the answers, including the link that provided each answer, so that you can find it again.
    • What is a galaxy?
    • What is the name of our galaxy?
    • What are the parts of a galaxy?
    • Why do we study galaxies?
    • How are galaxies classified? What do they look like?
    • Galaxy names are identified by a group of letters and numbers. What do they stand for?
    • Why do we study distant galaxies, if they are faint and hard to observe?
    • Here are some great sources to start your search (each team should choose one source):
  2. List the questions up on the board and share your answers. Note your source as you share. Did you all ‘converge’ on the same answer? Were there some places the answers disagreed? Go back and check your sources. Was the difference due to the groups interpretation? Or were the facts different?
  3. If you find disagreements, find another source that will confirm the one of the answers. Was one source more (or less) reliable than others?
  4. Congratulations! You have just crowdsourced your work.
  5. Use the information gathered by the students in this exercise to construct a Field Guide to Galaxies’ by using Field Guide to the Biodiversity of Your Schoolyard Activity.

Exercise 2: Use this Crowdsourcing in the Classroom lesson plan as a guide to teaching your students about the ‘power of the crowd’ and galaxies at the same time.

Activity 4: Observe Galaxies

Establishing an accurate mental model of the universe is a key concept in astronomy.

Your students should be familiar with how large distances are in our Universe from the Put things into Perspective activity. This is only one part the model. What actually makes up our Universe is the second.

Galaxies are part of the large-scale structure of our Universe, but they are not all the same. The following exercises are ways your students will become familiar with the variety of size and shapes of galaxies.

Exercise 1: To help your students practice their observing skills, try the lesson: Observe Like a Scientist

Exercise 2: Students should become familiar with the variety of shapes associated with galaxies. With Explore Galaxy Shapes lesson your students will seek out patterns on their own before introducing the Hubble Classification Scheme. Full lesson is found at

Exercise 3: For a quick exploration of the variety of shapes associated with galaxies, have your students watch this video Classification-Explore the Tuning Fork Lessons (This video is in Spanish with English subtitles).

Exercise 4: The following will allow students to experience the variety of shapes associated with galaxies and seek out patterns on their own. 

  1. Print pictures of many different types of galaxies from NASA (10-20 images).
  2. Then have your students develop their own classification systems. Take inspiration from the crowdsourcing exercises outlined above. (An example lesson can be found here.)
  3. Then have students compare their classification to that of Edwin Hubble.


Activity 5: Classify Galaxies!

First, You are a true collaborator!

Zooniverse enlists volunteers to help classify or describe images for many different Citizen Projects. They have some very simple rules to make sure they treat their collaborators well.

Zooniverse rules:

  • Tell people the purpose of the research and context (why it is important).
  • Don’t waste people’s time- if a machine can do it, people should stop doing it.
  • Participants are collaborators not subjects, or working for scientists.

Let’s get started:

  1. Log on to Galaxy Zoo! Create your own account and have fun. Go through a couple of classifications yourself to become familiar with the platform. 
  2. Before your students get started on categorizing galaxies you as the teacher will need to set up a Galaxy Zoo Navigator. When you classify galaxies in Galaxy Zoo, your answers are added to those submitted by the entire Galaxy Zoo community.
    • The Galaxy Zoo scientists have created a tool called Navigator that allows Zooites (Galaxy Zoo contributors) to form groups and analyze galaxies together. Within the Navigator tool, you can create many different graphs from the data your group analyzes. Use the Galaxy Zoo Guide for Teachers to set up your classes Galaxy Zoo Navigator.
  3. Time for your students to start classifying:
    • If you want your students classifying as an individual, just have them go to classify and get to work!
    • If you have set up groups in Navigator, have your students scroll down and click Navigator, or go to Galaxy Zoo Navigator to find your group.
  4. Once your students have joined your group, have them classify at least 25 galaxies (You choose a different goal. The more you classify, the more powerful your analysis will be.)
  5. Have your students use the student journal to keep track their observations.
  6. Make sure you are answering the questions correctly and really know what is being asked of you, by referencing the Zookeeping Guide. It will help you if you are stumped and keep you on track!
  7. Here are some good tools if you need guidance:
Activity 6: Analyze the Data

Before you get to analyzing the classifications you and the Zooites have made, you may want to think more about data collection and analysis by doing these exercises. Try them out!

Analyze Your Data

The Galaxy Zoo scientists have created a tool called Navigator that allows Zooites (Galaxy Zoo contributors) to form groups and analyze galaxies together. Within the Navigator tool, you can create many different graphs from the data your group analyzes. Use these the Short Student Guide to Navigator and the Student Guide to Graphing Tools in Navigator to help you learn to use Navigator.

Remember, Graphs Answer Questions

Explain to your students that a graph is created from a question in the investigator’s mind. If you want to see how one thing relates to another, you make a graph. Have your students create a couple of questions they could answer with they data they collected. 

Create your graphs:

  1. The Graph Data button brings you to the graphing tool. The title at the top of the page tells you to construct your question.
  2. The prompts on this page not only allow you to choose what information will be retrieved from the databases but also, remind you what the resulting graph tells you. 
    • Keep this in mind when you are making graphs and you will not lose track of what you are doing and why you are doing it.
  3. If you would like to have your students explore their data and the data generate by others (especially if your students are interested in other Zooniverse projects), use these more technical Zooniverse tools:
Extend your Experience

Join the conversation

Did you find something really strange? Are you wondering how to classify one of the galaxies? Something you would like to talk with others about? There are thousands of people ‘talking’ about their finds and all of the news on Galaxy Zoo Talk

Working with Collections in Talk

Remind your students about the dangers of sharing personal information online. This lesson is a good start.

Spread the Word

Once you have had some conversations with other people participating in Galaxy Zoo on ‘Talk’, think about how to share your story more broadly.

What is the most interesting or important thing you discovered from the galaxies you classified, the things you learned in preparing to classify or the work your group did together? Who in your community might want to know about your experience with Galaxy Zoo? Go through Modern Media Blitz: Sharing your Stories to create a social media campaign to share your results.

Extra Galaxy Zoo Lessons

Next Generation Science Standards & Common Core

NGSS Science Practices

  • Asking questions

  • Planning and carrying out investigations

  • Analyzing and interpreting data

  • Using mathematics and computational thinking

  • Constructing explanations

  • Engaging in argument from evidence

  • Obtaining, evaluating, and communicating information

NGSS Crosscutting Concepts

  • Patterns.Observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

  • Scale, proportion, and quantity. In considering phenomena, it is critical to recognize what is relevant at different measures of size, time, and energy and to recognize how changes in scale, proportion, or quantity affect a system’s structure or performance.

Common Core: English Language Arts Anchor Standards

  • CCSS.ELA-Literacy.CCRA.R.7 Integrate and evaluate content presented in diverse media and formats, including visually and quantitatively, as well as in words.
  • CCSS.ELA-Literacy.CCRA.L.1 Demonstrate command of the conventions of standard English grammar and usage when writing or speaking.

  • CCSS.ELA-Literacy.CCRA.L.2 Demonstrate command of the conventions of standard English capitalization, punctuation, and spelling when writing.

  • CCSS.ELA-LITERACY.CCRA.L.6 Acquire and use accurately a range of general academic and domain-specific words and phrases sufficient for reading, writing, speaking, and listening at the college and career readiness level; demonstrate independence in gathering vocabulary knowledge when encountering an unknown term important to comprehension or expression.

  • CCSS.ELA-Literacy.CCRA.SL.4 Present information, findings, and supporting evidence such that listeners can follow the line of reasoning and the organization, development, and style are appropriate to task, purpose, and audience.

  • CCSS.ELA-Literacy.CCRA.SL.5 Make strategic use of digital media and visual displays of data to express information and enhance understanding of presentations.

  • CCSS.ELA-Literacy.CCRA.W.1 Write arguments to support claims in an analysis of substantive topics or texts using valid reasoning and relevant and sufficient evidence.

  • CCSS.ELA-Literacy.CCRA.W.4 Produce clear and coherent writing in which the development,
  • organization, and style are appropriate to task, purpose, and audience.

  • CCSS.ELA-Literacy.CCRA.W.6 Use technology, including the Internet, to produce and publish writing and to interact and collaborate with others.

  • CCSS.ELA-Literacy.CCRA.W.7 Conduct short as well as more sustained research projects based on focused questions, demonstrating understanding of the subject under investigation.

  • CCSS.ELA-Literacy.CCRA.W.9 Draw evidence from literary or informational texts to support analysis, reflection, and research. 

  • CCSS.ELA-LITERACY.CCRA.W.10Write routinely over extended time frames (time for research, reflection, and revision) and shorter time frames (a single sitting or a day or two) for a range of tasks, purposes, and audiences.

Common Core: Standards for Mathematical Practice

  • CCSS.Math.Practice.MP2 Reason abstractly and quantitatively.
  • CCSS.Math.Practice.MP3 Construct viable arguments and critique the reasoning of others.
  • CCSS.MATH.PRACTICE.MP6 Attend to precision.
Citizen Science Toolkit
Citizen Science Toolkit

Check out our Citizen Science Toolkit, designed to help educators integrate citizen science projects into classroom curricula or afterschool programming.

It contains resources—including lessons, readings, and worksheets—to help communicate the value of citizen science to students and cultivate their sense of empowerment and impact when performing science investigations.

Appropriate for: 6th Grade - 12th Grade
Standards for: 6th Grade, 7th Grade, 8th Grade, 9th Grade, 10th Grade, 11th Grade, 12th Grade
Prep Time: 15 minutes
Activity Time: 180 minutes
Subjects: Analyzing & Interpreting Data, Physical Science