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What do you know?
  1. Study the visible- and infrared-light images of the Horsehead Nebula. Compare the features in each picture.
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  2. Why do astronomers use many different parts of the electromagnetic spectrum to view celestial objects?
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  3. The electromagnetic spectrum is composed of many different types of light. The following types of light are ordered from the lowest-energy waves to those of the highest energy: radio, microwave, infrared, visible, ultraviolet, X-ray, and gamma ray. If you could observe the Horsehead Nebula in any of these types of light, which would you choose and why?
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