dipper@utastro.UUCP (Debbie Byrd) (12/03/84)
This is the anniversary of the first encounter of a spacecraft with the planet Jupiter. More on Pioneer 10 -- in just a moment. December 3 The First Spacecraft at Jupiter On today's date in the year 1973 -- a great triumph for the U.S. space program -- the encounter of the planet Jupiter by a spacecraft. Pioneer 10 came only eighty-one thousand miles from the cloudtops of that planet. Pioneer 10 and its sister craft Pioneer 11 are true pioneers in space history. While several dozen spacecraft were sent to explore the inner solar system -- the neighborhood of the terrestrial planets Earth, Mercury, Venus and Mars -- no other spacecraft had ever gone to the outer solar system. To get there, they had to go through the asteroid belt -- a wide ring of dust, gravel and boulders in orbit around the sun. Space scientists believe a craft could safely travel through the asteroid belt -- but all doubt disappeared with the safe passage of the Pioneers. The Pioneers encountered Jupiter in 1973 and l974. They were forerunners of another pair of more sophisticated spacecraft -- the Voyagers 1 and 2. The Pioneers weren't equipped with the same elaborate instruments for imaging -- or picture-taking -- as the Voyagers. They didn't show us the spectacular photos that the Voyagers later did. But they did send back an immense volume of data on Jupiter and its moons. Pioneer 10 is now on its ways to the heliopause -- the boundary between our solar system and the unsampled open spaces of the galaxy at large. It'll be the first earthly craft to reach the heliopause probably sometime around the end of this decade. Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin