| Abstract: | This illustrated article touches on the history of telescopes, profiles three types of optical telescopes, and offers encouragement and a few pointers for amateur astronomers. In the history category, the article mentions the telescopes developed by Hans Lippershey and Galileo Galilei in the early 1600s. The discussions of the Hubble Space Telescope and the Next Generation Space Telescope, which is slated to follow Hubble, focus on the portion of the electromagnetic spectrum that each telescope can detect and the usefulness of observing in those regions of the spectrum. Part of the article's first page is also devoted to a summary of how optical telescopes as a group work. The second page provides descriptions and simple ray diagrams of refracting telescopes, reflecting telescopes, and catadiatropic telescopes. Copyright 2005 Eisenhower National Clearinghouse |