Who invented the telescope? What was it first used for?

In this new Hubblecast episode, Dr. J guides us through the first chapter of Eyes on the Skies, the International Astronomical Union’s official movie celebrating the telescope on its 400th anniversary in 2009. It has been 400 years since Galileo Galilei first walked out into a field and trained his telescope upon the heavens. To celebrate this extraordinary anniversary, a special series of Hubblecast podcasts is devoted to the telescope ? the historical development, the scientific importance, the technolog