SLAS Regular Meeting
Friday, October 18, 2013 7:30pm
Comet ISON - Comet of the Century?
Mr. Gary Kronk
A comet, named "ISON", has been discovered that may be visible in early morning daylight for a few days in November. When it was discovered, some comet specialists were calling it the Comet of the Century, because it was very much brighter than other comets seen at its great distance. But Comet ISON is making its first pass by the sun. The brightness of new comets has been notoriously difficult to predict accurately - many have turned out to be much dimmer than initially expected.
Comets, once feared as omens of future disaster, are now known to be relics from the formation of the solar system. The nucleus of a comet is a chunk of rock, dust, and ice only a few miles long. The relatively few comets that come closer to the sun than the orbit of Jupiter undergo a startling transformation. Sunlight heats the icy surface and causes gas and dust to be ejected from the nucleus. This material forms a head usually thousands of miles wide and tails often millions of miles long. While several new comets are discovered each year, few are bright enough to be seen without a telescope. Comet ISON could be one of these few. Its orbit will take it less than a solar diameter above the sun?s surface, which should make it very bright. However, at that distance, the sun?s gravity and energy may destroy the comet. Mr. Kronk will talk about the nature and composition of comets, and provide an update on the expected brightness and location of Comet ISON.
Gary Kronk has observed comets for almost four decades. He also writes extensively about them, providing articles to a number of scientific periodicals and authoring five books. During the past decade, since completion of the Kronk Observatory, he has been photographing comets as well as observing them.
Introduction of Officers