| Problems
          with Earth Telescopes
           Telescopes on the Earth’s surface
          all have one problem. They must look at the heavens through the Earth’s
          atmosphere. This causes distortion of the telescope
          images. Air currents make the images seem to move. Atmospheric gasses
          scatter light and make the images fuzzy. Both of these problems
          limit the amount of detail that can be seen through Earth-based
          telescopes. This limits how much astronomers can learn about the
          heavens. The distortion problem can be partially solved by building
          telescopes on the tops of mountains. Here the atmosphere is thinner,
          so distortion is not as bad, but still exists. 
          Astronomers have long known the
          only real way to fully solve the distortion problem: putting a
          telescope in orbit around the Earth. This dream came true in April of
          1990, when the Hubble Space Telescope was put in orbit around the
          Earth. The telescope is named after the American scientist Edwin P.
          Hubble, who made many important astronomical discoveries. The Hubble
          travels at an altitude of 380 miles, well above the atmosphere.
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