• Galaxies, planets, stars, solar systems, light years, and basic geometry of angles
• Students will probably have an understated idea of the size of the universe, not realize that the points of light they can observe in the sky are not necessarily individual stars, and believe that the size of an object in the sky is indicative of its distance from Earth. Gina Cash, Hammond Middle School, and Kirk Fitch, Tacoma Park Middle School.
  http://amazing-space.stsci.edu/resources/explorations/hdf/hdf-author.htm