Subject: Re: 4/18 Spoilers From: jak@ceres.physics.uiowa.edu Date: 1991-04-20, 10:38 Newsgroups: alt.tv.twin-peaks In article <41597@netnews.upenn.edu>, shiau@eniac.seas.upenn.edu (Mr. Liquid Cheeze) writes: > > In article <1991Apr19.095341.12408@pbs.org> mpax@pbs.org (Cool Bean) writes: >> >>COOO-ILLL! > > >> >>How often do Saturn and Jupiter meet? According to the scanty research >> >>I was able to do so far, it takes Jupiter 11.86 yrs to orbit the sun and >> >>it takes Saturn 29.46 yrs. So do they meet every 11.86 years? > > > > I don't think that is the physics of it. Unfortunately, I have no idea how > > often Saturn and Jupiter meet. I am pretty sure that regardless of whether > > Saturn and Jupiter could really be in alignment or not; they are. > > > > Saturn and Jupiter meet about once every 20 years. These are the correct orbital periods for these planets, and obviously Jupiter moves around the Sun faster that Saturn. However, as Jupiter is moving, Saturn is also moving, so after Jupiter has gone once around the Sun back its original position, Saturn has also moved along its orbit. So, for there to be a conjunction again, Jupiter has to travel a bit farther to catch up. Hence the 20 years rather than 12 years. Jeff Kouba Dept. of Physics and Astronomy University of Iowa INET: jak@ceres.physics.uiowa.edu