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Kentucky SkyTalk: The Instability of Planetary Systems

Speaker(s) / Presenter(s):
Tim Knauer (UK)

  One of the oldest problems in physics asks the question: Is the solar system stable? This problem dates back to Isaac Newton, who showed that a single planet orbiting the Sun would follow an ellipse with the Sun at one focus. The problem becomes much more complicated when you consider the eight other planets, all exerting small gravitational perturbations on each body.

There is no analytical solution to this problem. This classical question has been revived with the discovery of multiple expoplanet systems, which will be discussed.


 The University of Kentucky Department of Physics and Astronomy is pleased to welcome the public to our astronomical observatory. Part of our program of public outreach is a presentation on an interesting topic in astronomy followed by a visit to the observatory.  The Kentucky SkyTalk is held on the second Thursday of each month.  A 45 minute program on astronomy will begin at 8:00 PM in Room 155 of the Chemistry-Physics Building. After the presentation, you are invited to view the sky through our 20-inch telescope, weather permitting.

Free parking is available on the top floor of parking structure #2, next to the observatory. With the exception of paid parking, without a valid parking permit, leaving your vehicle somewhere other than next to the observatory will result in a parking citation.

All are welcome and there is no charge. Tell your neighbors. Bring your kids.

Weather Caveat: If the university closes for a weather emergency, the SkyTalk will be postponed and the observatory will not be open.

A SkyTalk flyer in pdf format, sky maps for April, and a link to a campus map are available here: