astronomy_page essay_on_astronomy astronomy astronomy_defined astronomy_arguments naked_eye_astronomy light_pollution Kielder_Observatory remote_telescope WorldWide_Telescope Google_Sky telescope.org harvard.edu/OWN eyes-on-the-skies.org commercial_services telescope_cameras telescope planetarium_software_projects astronomy_involves_telescopes lens basic_idea_of_a_lens Hans_Lippershey creator telescope_bertini result_of_knowledge Galileo_Galilei Giovanni_Demisiani heliocentrism suppressing_facts stellar_parallax heliometer stellar_parallax_observed scale_of_the_universe