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Galaxy Cluster Abell 2744
Half size lp galaxy cluster abell 2744 2x
(6.17 MB)

Photo taken by the Hubble Space Telescope

This image shows Abell 2744, a cluster of galaxies that provide the 'lens' needed to image the faint galaxies behind the cluster.

Facts of interest about the image

This image contains multiple examples of gravitationally lensed galaxies, as shown by the many blue streaks across the picture.

Classroom activity

Included is an inquiry-based classroom activity that focuses on the image and text.


This image from the Hubble Space Telescope shows the Abell 2744 cluster of galaxies. This massive cluster acts as a gravitational lens by bending the light coming from the faint galaxies located behind the cluster. Scattered among the cluster galaxies are blue streaks of light which are the distorted images of distant galaxies. This long-exposure image was the first of a set of Hubble Frontier Field observations of massive galaxy clusters. The program is designed to study faint, early galaxies revealed by gravitational lensing. The lithograph includes a classroom activity.

11-12, but the material can be adapted for use in other grades at the teacher's discretion
How to use in the classroom

Teachers can use this lithograph as:

An example of a galaxy cluster. Use the inquiry-based classroom activity called In Search of Galaxy Clusters that is included with the PDF lithograph.

An engagement tool in an inquiry-based lesson. Have students study the images on the lithograph. Ask them to write down any questions they have about the images. When the students are finished, their questions can be used in a variety of ways:

  • Ask students to find the answers to their questions by reading the text on the lithograph and/or the related materials listed below.

  • Have students exchange papers so that each student has someone else's questions. Then have them find the answers to the other students' questions by reading the text on the lithograph and/or the related materials listed below.

  • Gather the questions into a list by asking students to volunteer to read their questions while you or another student records them. Ask students to raise their hands if they had the same or a similar question. Count the number of hands raised and record this number next to the question. Once all the student questions have been added to the list, have students search for the answers to their questions in the text on the back of the lithograph. When they complete that task, ask them to decide if each of their questions was answered completely, answered partially, or not answered at all. Go through the original list and place an "A" in front of the questions that were answered completely, a "P" for those that were partially answered, and an "N" for those that were not answered at all. Determine if the most commonly asked questions were also answered completely. Encourage students to do further research to find answers to the unanswered questions.

A content reading tool. Have students read the text on the lithograph and then write a quiz for the class.

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