Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site utastro.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!sdcsvax!sdcrdcf!hplabs!hao!seismo!ut-sally!utastro!dipper From: dipper@utastro.UUCP (Debbie Byrd) Newsgroups: net.astro Subject: StarDate: December 5 Navigation by the Stars Message-ID: <874@utastro.UUCP> Date: Wed, 5-Dec-84 02:00:20 EST Article-I.D.: utastro.874 Posted: Wed Dec 5 02:00:20 1984 Date-Received: Sat, 8-Dec-84 06:31:55 EST Organization: UTexas Astronomy Dept., Austin, Texas Lines: 37 Early South Pacific sailors developed a unique way of guiding their ships by the stars. More -- right after this. December 5 Navigation by the Stars Even without the use of special instruments for navigation, it's possible to guide a ship at sea by the stars. Beginning several thousand years ago, Polynesian island-dwellers in the South Pacific used what are called "star paths" to find their way between islands hundreds of miles apart. A star path is just the use of a sequence of stars rising up from the east or setting in the west, and marking a particular direction on the horizon -- the direction to another island where the sailor wants to go. The star paths guiding sailors from one island to another used to be well known, though each star path would of course evolve through the year as different stars gradually became visible with the change of seasons. At any moment the star actually guiding the sailor would be low in the sky -- a star at the bottom of the path that has just risen or is about to set. The voyagers steer toward that star, which they know is in the direction of the island they wish to visit. Pretty soon that star has risen too high or has set. Then the next star in the path -- in approximately the same location near the horizon -- is used in its place. In addition to knowing the star paths, the island navigators also had to know ocean currents and drifts, and to correct their courses accordingly. This remarkable skill in navigating by the stars was handed down by word of mouth. Yet it had been in use for over a millenium before the Europeans -- and their instruments -- arrived four hundred years ago. Script by Diana Hadley and Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin