Citizen Science: Galaxy Zoo

The citizen science project known as Galaxy Zoo has long been one of my regular activities in astronomy lab.  I like the idea of my students contributing to the data base.  I also use the activity to use a special format known as “backwards-fading-scaffolding.”

Science consists of several steps sometimes taught in elementary school as the scientific method.  Students generally know how to arrive at a conclusion, so all I do in Phase 1 is to provide all the other steps but have students write a finely tuned conclusion.

Then phase by phase I remove another step, requiring the students to complete it.  This “backwards-fading-scaffolding” concludes with the students carrying out every step and then reflecting on their learning.

Below is a copy of the activity report students turned-in for Galaxy Zoo.  You are welcome to cut-and-paste and complete it yourself, or amend to fit your circumstances and assign it to your students.


Student: ____________________________

Section __________Date: _____________

                                                       Classifying Galaxies: Galaxy Zoo —  

Big Idea: The countless galaxies of stars spread throughout the universe have characteristics that can be observed and classified.

Computer Setup

  1. Google “ Zooniverse – Real Science Online”
  2. Register to take part
    1. Log in: _________________
    2. Password: ___________________ (Not required here but write it down!)
    3. Choose GALAXY ZOO

Phase I: Exploration (10 points)

  1. WITHOUT looking in your book, your class notes, or the Internet, write a reasonably good definition of a galaxy in the space below. Include one rough sketch of what a galaxy looks like. Definition and sketch:







  1. In Galaxy Zoo click on “Begin Classifying” > “Examples” and look at the image samples. Draw an example of the two basic shapes in the table below:
Smooth Features or disk
  1. Click on CLASSIFY and begin observing galaxies. Please fully classify 5 (five) galaxies. The computer may ask more questions or different questions than asked for on this report. Please answer all the Galaxy Zoo questions to the best of your ability. First decide which kind of object your image is, then record your answers in that column. You need only record what’s asked here. Record the results here:
Image #1







Smooth? Features or disk? Star or artifact?
Completely? Edge-on?
In-between? Bar?  




Cigar Shaped? Spiral arms?
Oddity? Oddity?


Image #2







Smooth? Features or disk? Star or artifact?
Completely? Edge-on?
In-between? Bar?  




Cigar Shaped? Spiral arms?
Oddity? Oddity?


Image #3







Smooth? Features or disk? Star or artifact?
Completely? Edge-on?
In-between? Bar?  




Cigar Shaped? Spiral arms?
Oddity? Oddity?


Image #4







Smooth? Features or disk? Star or artifact?
Completely? Edge-on?
In-between? Bar?  




Cigar Shaped? Spiral arms?
Oddity? Oddity?


Image #5







Smooth? Features or disk? Star or artifact?
Completely? Edge-on?
In-between? Bar?  




Cigar Shaped? Spiral arms?
Oddity? Oddity?


Phase II: Does the Evidence Match the Conclusion? (15 points)

Enter Galaxy Zoo and classify ten (10) more images. Keep a record of your observations in Data Table 1 below.



Data Table 1








Clockwise Spiral Counterclockwise Edge-on or unclear
                                   Elliptical (smooth) galaxies
Artifact/Star/Don’t Know Merging Galaxies


  1. Consider the research question “what type of galaxy is most common?¨ If a student proposed a generalization that “most galaxies are ellipticalwould you agree or disagree with the generalization based on the evidence you collected SO FAR?

Analyze the evidence of how many of each type of galaxy show up in your data tables to pursue this question. Explain your reasoning and provide specific evidence either from the above questions or from evidence you yourself generate using Galaxy Zoo. Include a description of a weakness in the research and conclude with a deeper question.

Evidence-based Conclusion Statement:









Phase III: What Conclusions Can You Draw From This Evidence?

                                                                                                                 (15 points)

Galaxies are observed to have numerous different shapes. Consider the research question “which direction do spiral galaxies usually spin?¨ What conclusions and generalizations can you make from the following data collected by a student in terms of DO SPIRALS GENERALLY SPIN CLOCKWISE OR COUNTER-CLOCKWISE?

Explain your reasoning and provide specific evidence, with sketches if necessary, to support your reasoning.

  Clockwise Spiral Counterclockwise spiral Edge-on /Unclear

Data Table 2








  1. Evidence-based Conclusion



Phase IV: What Evidence Do You Need To Pursue? (20 points)

Imagine that you have been assigned the task of designing a scientific observation plan for your favorite news blog about galaxies that collide and merge into a single, larger galaxy. Describe precisely what evidence you would need to collect in order to answer the research question of, “What fraction of galaxies observed appear to be in the process of merging with other galaxies?”


  1. Create a detailed, step-by-step description of evidence that needs to be collected and a complete explanation of how this could be done—not just “look and see how many are merging,” but exactly what would someone need to do, step-by-step, to accomplish this. Create a blank table in which to collect data and impose a structure on it. Remember to include as your last step #? “Write an evidence based conclusion statement.” The goal is to be precise and detailed enough that someone else could follow your procedure and reproduce your observation.








Phase V: Formulate a Question, Pursue Evidence, and Justify Your Conclusion (30 points)

Your task is to design an answerable research question, propose a plan to pursue evidence, collect data using Galaxy Zoo (or another suitable source pre-approved by your teacher), and create an evidence-based conclusion about the nature and/or frequency of galaxies you observe. Refer to the last page of this document for descriptions of each step.

Research Report:

  1. Specific Research Question:





  1. Step-by-Step Procedure, with sketches if needed, to collect evidence:












  1. Data Table and Results:
















  1. Evidence-based Conclusion Statement:








Phase VI: Summary (10 points)

  1. Create a 50 to 100-word summary, in your own words, that describes the nature and frequency of different types of galaxies we observe in the universe. You should cite specific evidence you have collected in this lab activity, not describe what you have learned in lecture or elsewhere. Feel free to create and label sketches to illustrate your response.

























Successful Inquiry


  1. Specific Research Question: One question clearly stated.
    1. This should be an imaginative question that requires the measurement of something to discover a pattern.
    2. Collecting evidence in the form of numbers is needed to analyze, synthesize or compare. The best questions are not such that you could look up the answer, but an inquiry of depth, about an interesting topic.
  • GOOD EXAMPLE: ”How does the time of sunset change over the course of a year at this location?”
  • POOR EXAMPLE: “When does the Sun set on September 25?”


  1. Step-by-Step Procedure to Collect Evidence: Here you must create a plausible method for collecting and organizing data.
    1. The data collected should be numbers, measuring different aspects of the situation described in the question.
    2. Plan the structure, the organization, you will impose on the data. Usually this begins with a table. See the attached page for more details about making a table. Be ready and willing to add to and adjust your plans as you collect data.   Yes, that may mean you might have to retrace your steps.


  1. Results and Data Table: A table that organizes the numbers is one simple, traditional way to present data collected.
    1. Data should be specific and exact. Don’t be afraid of decimals.
    2. Measurements (numbers) might describe changes to important factors or present a way of seeing similarities or differences in various factors. Numbers can be used for comparisons and analysis.
    3. Organize the numbers in the table you planned in 2 above.
    4. Having more than one variable suggests that a graph might be useful. Your graph would compare and contrast the data collected.   Choose a scale for the graph that gives a clearer picture of the comparison.


  1. Evidence-based Conclusion Statement: This is a multi-sentence conclusion that includes facts and numbers from the collected data, and uses logic to explain the pattern of those numbers.
    1. Be explicit about the data, using at least one example to illustrate how the logical process was carried out. Your reasoning should make some sense of the numbers, telling what they mean.
    2. Be careful stating what the data supports and doesn’t support. Use your words wisely. Defend your interpretation of the data.
    3. Acknowledge weaknesses. All research has weaknesses because all models are wrong. Clearly describe any problems or uncertainties.
    4. Raise a “deeper question” that might warrant more research. A deeper question could be one that is not readily found answered elsewhere, a question that makes someone wonder if one or some of their preconceptions are wrong, or gives a profound insight into understanding the universe.   (This is possibly the most difficult expectation.)



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