[Illustration: Cover: A cylindrical projection of Jupiter’s atmosphere was made from ten color images taken by Voyager 1 during a single ten-hour rotation of the planet.] [Illustration: A computer-generated mosaic of Voyager 1 pictures showing Jupiter from directly below the south pole. This view shows features as far north as 20 degrees latitude. The black area at the Pole results from missing information.] Voyager Encounters Jupiter July 1979 NASA National Aeronautics and Space Administration CONTENTS Foreword 3 Introduction 4 Images of Jupiter and Its Satellites 6 The Voyager Mission 37 Scientific Highlights 39 Jupiter 39 Amalthea 39 Io 39 Europa 39 Ganymede 39 Callisto 39 The Magnetosphere 40 Scientific investigations of the Voyager mission 40 [Illustration: _A Titan/Centaur rocket served as the launch vehicle for Voyager and was the last planned use of this type of launch vehicle prior to the era of the Space Transportation System (Shuttle Orbiter)._] Foreword In late summer of 1977, the United States launched two unmanned Voyager spacecraft on an extensive reconnaissance of the outer planets, a decade-long odyssey that could take them to 3 planets and as many as 18 planetary satellites. The first encounter was with the giant Jovian planetary system, 645 million kilometers (400 million miles) away. Passing by Jupiter and its complex satellite system in 1979, the Voyager spacecraft have collected and returned to Earth an enormous amount of data and information that may prove to be a keystone in understanding our solar system.