Journey Into Spectroscopy
A spectroscope is an instrument that splits the light from an astronomical object into its individual wavelengths or colors. Students will construct their own spectroscope as they explore and observe spectra of familiar light sources. Extension activities expand their understanding of different kinds of spectra and sharpen their observing skills.
Grades 6-8, 9-12
Large telescope designs have changed significantly over the last few decades, with a growing emphasis on using segmented mirrors. This activity series consists of 4 challenges that students complete to discover how and why astronomers design and use segmented mirror telescopes.
Can gelatin (like Jell-O) change the speed of light? What is the index of refraction for the gelatin that you buy in a grocery store? Students will investigate the refractive properties of gelatin to calculate its index of refraction and discover that as light travels through the gelatin, its speed and wavelength change. This activity offers students a challenge: to find the index of refraction of an everyday, intriguing, translucent substance outside the standard listing of materials and refraction indexes.
In this activity, students learn about the different telescopes and instruments that are available at McDonald Observatory using the “What Are Astronomers Doing” web site. They use this information to help a group of scientists decide which of McDonald Observatory's resources will best suit their projects. As students learn about the instruments, they also learn about the uses of electromagnetic waves in technological applications (telescopes and instruments). They also are thinking critically about what specific combinations of tools an astronomer requires to resolve each problem situation. We recommend following this activity with “Telescope Allocation Committee.”
Telescope Allocation Committee
This activity acquaints students with the telescopes and instruments available at McDonald Observatory. Astronomers apply for observing time on research telescopes. They must communicate their research objectives clearly and concisely to members of the McDonald Observatory Telescope Allocation Committee. Based on an astronomer’s research proposal, the TAC will decide who observes on which telescope at what time. We strongly recommend that students do “Astro-Madness” before this activity.
Delta, Delta, Delta
In this experiment, students construct an equilateral triangle using graph paper, pencil, protractor and a ruler. They also make a “laser triangle” using a laser pointer and front-silvered mirrors. Students can use the geometric properties of an equilateral triangle combined with their understanding of the Law of Reflection to decide how to place the mirrors at each vertex so that the laser triangle fits their equilateral triangle.
Students witness light refracting through air every day. On hot days, “ripples” rise from the ground or roadways. Stars twinkle in the night sky. The Sun looks squashed on the horizon at sunrise and sunset. Students can explore the interaction between air and light through this activity to understand more complicated everyday phenomena.
In this activity, students test the Law of Reflection based on experimental evidence. However, the silvered glass mirrors present a twist. As light travels from air into glass it changes direction (refracts), reflects off the shiny metal back coating, then changes direction again upon emerging from the glass. The reflected ray may not match students’ expectations, and they must work out what happened as the light traveled into and out of the mirror. Large astronomical telescopes use curved mirrors (rigid glass or polymer coated with a metal) to focus starlight on electronic detectors.