dipper@utastro.UUCP (Debbie Byrd) (10/05/85)
The second man-made comet was even more successful than the first. More -- after this. October 5 The Second Artifical Comet Two days after Christmas last year, scientists made the first artifical comet. Two containers of barium-laced copper oxide crystals were released from a satellite orbiting high above the surface of the Earth. Out there in space, the expanding cloud of crystals developed into a long tail -- similar to the tail of a comet. The purpose of this man-made comet mission was to study the solar wind -- electrically charged particles from the sun. The crystals were strewn out in the region of space where the solar wind encounters the Earth's magnetic field. As the solar wind flowed past the artificial comet, it electrically charged the barium. A glowing purplish ion tail was produced that dragged out for more than ten thousand miles. The solar wind was moving so fast -- about 350 miles per second -- that the tail lasted only about fifteen minutes. Data from the first artificial comet surprised researchers somewhat. The ions in the barium tail didn't flow WITH the solar wind as anticipated. Instead the ionized barium appeared to move at right angles to the flow. Last July 18th a second artifical comet was released from the same satellite -- with even better results. This time the solar wind was moving not quite as fast -- and this second tail lasted almost half an hour. The data on both artificial comets -- from ground-based observers and from satellites in space -- will aid in our understanding of how the solar wind interacts with the tails of real comets -- and with the Earth's magnetic field. Script by Diana Hadley and Deborah Byrd. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin