Unlike the summit of most other mountains, the one on Kitt Peak ]supports a community of scientists. They are not alpine biologists, but astronomers, a mountaintop community of sky-watchers, whose tools are an assortment of telescopes. Taking advantage of the clear and unpolluted atmosphere, these scientists exploit an arsenal of telescopes to explore the universe.
Reflecting on a model
Many of the telescopes located atop of Kitt Peak use reflecting surfaces to collect light and magnify observed images. In this activity, you’ll model this process. Using a simple makeup mirror, flat mirror, and a hand lens, you’ll observe the basic operation of a reflecting telescope.
Materials: Makeup mirror Flat mirror Clay Hand lens Bright light source (lamp)
CAUTION: Never use this telescope model or other types of viewing tools to look at the sun or other very bright objects.
Steps: 1. Position a makeup mirror on you desktop. Aim the mirror at the classroom light source that your instructor will assemble.
2. Position a flat mirror on your desktop, using a lump of clay as a base so that the mirror stands erect. Angle and position the flat mirror so that you can see the reflection from the makeup mirror.
3. Turn off the classroom lights. Adjust the angle and placement of both mirrors so that you can see the image of the light source in your flat mirror.
4. Use a hand lens to examine this image.
Questions1. How might the diameter of the makeup mirror affect the image? (The larger the mirror, the more light it can collect. This means that larger mirrors can detect fainter light sources.)
2. Why is the position of the flat mirror critical? (It must be positioned to reflect the image from the makeup mirror to the observer’s eye.)
3. What was the role of the hand lens? (It magnified the reflected image.)
Ray diagrams
Many of the telescopes on the top of Kitt Peak use mirrored lenses that collect, magnify and reflect the image to an electronic sensor. These sensors have taken the place of the optical eyepieces through which astronomers historically viewed the sky. Even so, the path of light into and through the telescope body remains the same. Use print and online resources to uncover ray diagrams that illustrate these paths. Then draw a cutaway view of a reflecting telescope that includes a ray diagram showing the path of light.
Critical cut
Scientists are always faced with funding issues. When grants or other forms of financial support don’t come through, they may be forced to shut down research projects. Suppose the funding to maintain the peak’s 23 telescopes was dramatically cut. If you were in charge, which telescope would you least defend from budget cuts? Why? Which telescope would you most defend? Explain. Then, list the 23 telescopes in order of most important to least important observational tools. Be prepared to defend your list order against the list order of classmates. In an open forum, discuss and compare the advantages and potential understanding associated with Kitt’s different telescopes.
Map it
Check out the photo on page 42. Can you construct a map from this image that illustrates the relative location of the peak’s observational tools? Try it and find out. On a sheet of graph paper, create a map of this area. Include the locations and descriptions of all telescopes. Can you turn this 2D map into a 3D model? If appropriate create a three-dimensional model of the area using clay and other art materials.
