Light and the Electromagnetic Spectrum Questions Astronomy Name___________________ 1. Place the following electromagnetic waves in order from shortest wavelength to longest wavelength: microwaves, red light, violet light, radio waves, x-rays, gamma rays, infrared 2. Place the following electromagnetic waves in order from lowest energy to highest energy: microwaves, red light, violet light, radio waves, x-rays, gamma rays, infrared 3. Use the speed of light to determine the frequency of an electromagnetic wave that has a wavelength of 0.4 meters (show your work and your calculation). 4. Jupiter is approximately 5 times farther away from the Sun than Earth is. If you were on Jupiter and you looked back at the Sun, how would its brightness compare to its brightness on Earth? (show your work and your calculation). 5. Light gets dimmer as you get farther away from a source according to the inverse square law (like in the previous question). Why do you think it is so challenging for astronomers to view stars and galaxies that are millions or billions of light years away from Earth? Because light gets blocked and scattered by dust and gas, it is sometimes helpful to look at the same object in different frequencies. Look at the images of the multiwavelength of the Milky Way. Each of these images is a picture of our Milky Way galaxy; we will see later that we are just one star in a group of billions. This is like being one tree in a forest and looking at the entire forest surrounding us. These are the same pictures of the Milky Way, but they are taken at different wavelengths. 6. Which types of telescopes would be used to look for high energy wavelengths and which types of telescopes would be used to look for low energy wavelengths? 7. Look at the gamma ray image. Where in the galaxy do you see the highest energy radiation (shown in red) coming from? 8. Look at the emission line spectrum for hydrogen. The absorption spectrum of a star is shown in the image below it. 9. If you saw these two spectra side-by-side, what could you infer about the star’s chemical makeup? Explain. 10. Consider the same spectra. What could you infer about the star’s motion? Explain. 11. Consider the images of the different stars. Carefully look at the colors of these stars. Which star has the highest temperature and which star has the lowest temperature? Justify your answer. 12. If you wanted to detect temperature variations on the moon of another planet, what type of wavelengths might you want to observe? 13. When you see an image of a star or galaxy in radio waves and different colors, are you really “seeing” the radio waves? Explain what you are seeing.