AUDIO: Comets were born with the sun and the planets four and a half billion years ago. But unlike the planets, the primitive ices and dust of comets have remained unchanged. They are windows into time, back to our begining. Comets are woven into our history and our legends. For centuries they were feared as evil omens, harbingers of ill fortune. Apprehension and superstition greeted their arrival. But even as some feared these mysterious freaks in the night sky, others not affected by superstition saw them as part of the natural world that they wanted to understand. Among them was the English astronomer Edmond Halley. He not only tracked the great comet of 1682 and calculated its course, but he was also perceptive enough to realize that this comet had been observed many times in the past. He predicted that it would return every 76 years, again and again. Halley was ridiculed for his prediction, but the comet's next return proved that he was right. When this comet, Halley's Comet, returned in 1910, millions of people were fascinated by its appearance. This greatest-of-all-comets was intensively studied by scientists and photographed for the first time. VIDEO DESCRIPTION: Zoom out from observatory dome to comet in the sky. Photos of old art depicting comets as evil beings. Art depicting rennaissance astronomers. Picture of Edmond Halley. Drawing depicting 1910 public viewing the comet.