http://www.reuters.com/newsArticle.jhtml;jsessionid=SIL3UERWX5D3YCRBAEKSFFA? type=scienceNews&storyID=1822299
Astronomers unveiled a quick new recipe for creating big planets, using high-powered supercomputer calculations to show these gassy giants could form in hundreds of years, instead of millions. Most scientists have maintained that planets the size of Jupiter, the largest in our solar system, take several million years to coalesce out of the massive disks of cosmic debris that surround infant stars. But research published in Thursday's edition of the journal Science indicates that these monstrous disks tend to break up after just a few turns around their star. As the disk breaks up, matter begins to clump together quickly and starts to draw in the gases that would otherwise go to form vapor shrouds around Jupiter-style gas giant planets. Planets have to form during this early period or the cosmic gas and dust that would make them is pulled away and dissipated by radiation from nearby stars, U.S. and Canadian scientists found. "If a big gas planet can't form quickly, it probably won't form at all," astronomer Thomas Quinn of the University of Washington, one of the authors of the Science report, said in a telephone interview. Recent research on so-called extrasolar planets orbiting stars outside our solar system lends support to this theory. JUPITER-TYPE PLANETS The fact that astronomers have detected more than 100 Jupiter-type gas giant planets orbiting other stars besides our sun indicates that these big planets are fairly common, Quinn said. If Quinn and his colleagues are correct, this means that most big planets formed quickly; if they had followed the multimillion-year model, gas giants would be expected to be rare, with all the raw materials being sucked off by neighboring stars over time. Earlier scientists had theorized that the so-called protoplanetary disks could congeal quickly to create big planets, but lacked the computing power to create a simulation that would show this, Quinn said. Supercomputers running powerful programs designed to track the origins of the cosmos were able to make the detailed calculations showing how these big planets might form fast. "It was pretty clear cut," Quinn said, speaking of the computer simulation. "We just looked at our visualization and saw those are planets, definitely of the right masses. They're even rotating as fast as we'd expect, as we see Jupiter rotating. Quinn said the computer models did not pinpoint any actual big planets that formed quickly, but indicated that this scenario could work. xponent Plop Maru rob _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
