Lesson Plan


By the end of this project, the student will be able to:

  • Appreciate the variety and beauty of objects in the sky and the ability of a research telescope to obtain quantitative information about these objects.
  • Use the SkyServer Navigation Tool to identify objects and record celestial coordinates.
  • Identify the type of galaxy from its image.
  • Associate star brightness and magnitude.
  • Associate star color with relative magnitude observed through different filters.
  • Work in a group to complete the project and participate in a peer review.


Students should have some experience in looking at the night sky and considering the objects they see. They should also have some idea of what a telescope is and what a color filter is. Students should be able to use a web browser and navigate between windows.


  • Celestial Coordinates – The two angular coordinates that give the position of an object on the celestial sphere, an imaginary sphere that surrounds Earth and rotates with the Earth.
  • Right Ascension – abbreviated (ra) – The longitude of an object on the celestial sphere. Zero is defined by the vernal equinox, the position of the Sun on the first day of spring. On SkyServer, right ascension runs from zero to 360 degrees.
  • Declination – abbreviated (dec) – The latitude of an object on the celestial sphere. Declination runs from 90 degrees above Earth’s north pole to -90 degrees above the Earth’s south pole.
  • The following terms are defined in the student project:
  • Light
  • Star
  • Galaxy
  • Star cluster
  • Galaxy cluster
  • Asteroid
  • Spectrum
  • Ghost
  • SDSS
  • Skyserver
  • Navigation Tool
  • Quasar
  • Magnitude
  • Filter


Students should work in groups of two or three. Each group will need a computer with a web browser. Each group will also need a copy of the Scavenger Hunt worksheet PDF. If you can’t open the PDF, use this list instead.

If your students have not worked with color filters, a class set would be helpful. You can order filters from science equipment suppliers – a good set is the Arbor Scientific Color Filters Kit 33-0190 ($12.00), or you can use colored cellophane from art supply stores. It is also helpful to have a classroom TV monitor or projection device to demonstrate website images.

Preparation Time

The only preparation time required is to set up computers, provide the link to the students, and to duplicate the worksheet. However, before you require students to do so, you should to read the information about the Sloan Digital Sky Survey (SDSS) from SkyServer. In addition, you may find it helpful to look at samples of the objects students will be seeking from SkyServer’s Famous Places.

Also, you are strongly advised to try the activity beforehand, and practice with the Navigation Tool.

Classroom Time

Allow between two and three 45-minute periods, depending on the type of class and the prior knowledge and ability of the students.

Procedure (Students work in groups of 2 or 3)

  1. Have the students read the “Welcome” statement on the SkyServer home page. Explain that they will be using a tool that astronomers are currently using for research. If time permits have students read About SDSS and The SDSS Telescopes and write down important facts. Call on each group to share one fact. Show some of the pictures from Famous Places on SkyServer. If only two class periods are available for this project, do this introduction the day before and assign the reading for homework.
  2. If students are not familiar with color filters, distribute filters and have students look at different colored objects through the filters and describe what they observe.
  3. Have students read through the project and practice using the Navigation Tool. With less able students, you may need to read through the explanations and instructions as a class.
  4. Distribute the worksheets and set the stop time for collection of the worksheets. Spot check student work.
  5. Allow time for students to exchange papers and use the Navigation Tool to enter the coordinates and check the objects listed. Explain that peer review is an important part of science research.

Follow-up activities

The projects Asteroids, Types of Stars, Colors of Stars, and Galaxies are natural extensions of this project. In addition, once students have completed this project and feel some control over the SDSS data, it could be meaningful to write a report on the major discoveries of SDSS or the SDSS instruments.

A quick and useful homework assignment is to have students summarize what they have learned from the project, to list what they have learned previously that helped them understand the project, and to state what they liked and what they did not like about the project. Click here to see the assignment.

Few or no computer classrooms

This activity requires the use of a computer. However, students work in groups of 2 to 3, and only one computer is required per group. If computers are available to the students at home or in a library, the activity could be introduced in class and continued outside the classroom.

Home schoolers

The project can be done by an individual rather than a group. It would be best if a student working alone could exchange his or her results with another student to check the work