Curricular Unit: Spectroscopy

Students create and use spectrographs. click for copyright

Grade: 7 (6-8)

Summary

Students learn how using a spectrograph helps us understand the composition of light sources. Using simple materials and holographic diffraction gratings (available online at a variety of sites, including Edmund Scientifics and the Rainbow Symphony Store for ~50 cents each), students create and customize their own spectrographs - just like engineers. They gather data about different light sources, make comparisons between sources, and theorize about their composition. Before building spectrographs, students learn and apply several methods to identify and interpret patterns, specifically different ways of displaying visual spectra. They also use spectral data from the Cassini mission to Saturn and its moon, Titan, to determine the chemical composition of the planet's rings and its moon's atmosphere.

Engineering Connection

Spectrographs are used in ground-based telescopes and in space to help astronomers answer questions about what makes up the atmospheres of distant planets and stars. Engineers create these spectrographs to advance our knowledge of the universe. Spectrographs are designed very specifically to analyze certain types of light. The spectrograph materials used determine which spectral lines can be seen. Creating spectrographs to operate from space satellites is a special challenge, requiring the development of lightweight and durable materials and equipment that can withstand space travel.

Keywords: angle, color, diffraction, light, patterns, prism, space, spectra, spectrograph

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