Alime.159 net.space utcsrgv!utzoo!decvax!duke!chico!harpo!npois!houxi!houxg!lime!gdg Mon Feb 8 00:24:53 1982 RE: dennis' reply to Horseshoe Orbits speaking, angular velocity is the rate at which an orbiting body subtends a given angle relative to the orbital *focus* (CG), which, in the case of relatively light moons orbiting relatively round, heavy planets, can be considered to be the center of the planet. Simply put, radians/second. *It has nothing to do with speed relative to the surface.* For example, a geosynchronous satellite has no motion relative to the Earth's surface, yet its angular velocity is considerable. If the earth suddenly stopped rotating, the satellite's angular velocity would remain the same (360 degrees/day), and it would remain in orbit at the original altitude. (Of course it would no longer be geosync either.) We just tend to think of orbital speeds as relative to the planet surface, but that is *apparent* angular velocity. Luckily for us, that's all it is. If the earth had no angular velocity (spin) of its own we wouldn't be able to have geosync satellites at all because no matter what orbit we put them in they'd always have some velocity relative to the surface. - Glenn Golden ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.