Here's a workup I did on this year's Leonid forecast for Saturday night for another newsgroup. Additionally, on Saturday morning at 6:45 am, Mercury will make its brightest appearance of the year in the east/southeast sky. ==================== The S&T calendar states that for this year's Leonids: "Elsewhere on the continent [other than the east coast of the United States], zero Leonids will be visible no matter what the shower is doing at the time." http://skytonight.com:80/observing/ataglance At 4:45 UTC 11/19/2006 (about 1:45am EST), there is predicated maximal outburst with the radiant in the "head" of Leo between eps Leo and eta Leo. The best viewing position at the time of the predicted outburst is in Europe. See Visibility Map at http://www.arm.ac.uk/leonid/index.html . The predicted zenithal hourly rate for the 2006 Leonids is between 10 and 150+? with a high degree of uncertainty. This is a _zenithal_ limiting magnitude estimate. When the radiant is low on the horizon, you see a much lower rate per hour, but a better potential exists to see horizontal grazers - bright bolides streaking horizontally across the sky.
From Salt Lake, eps Leo and the radiant will just be rising over the horizon in the East.
The ZHR time prediction is just that, a maximum peak around which a broader shower period will occur. There is a higher degree of uncertainty about the nature and extent of this year's Leonids. Meteor showers occur when the Earth passes through the tracks of a comet - in this case a passage of Comet 55P/Tempel-Tuttle that occured in 1932. There are several of these historical paths - each of which generates a unique cloud of particulars that disperse over time. See Map of Leoniod stream cloud particles at the IMCE: http://www.imcce.fr/en/ephemerides/phenomenes/meteor/DATABASE/Leonids/2006/ - and at Dan Asher's site: http://www.arm.ac.uk/leonid/dust2006.html Cloud-stream interception is predicted to be very well placed for this year, but because the particles were initially deposited from Comet 55P/Tempel-Tuttle in 1932, most of the heavy particles are believed to have dispersed. The initial McNaught & Asher (1999) prediction was that this would potentially be a very good year for a Leonid shower. Follow-up analysis by Vaubaillon et al. (2005a) (see the IMCEE website above) indicated that the small nature of the particles might result in a shower with a high number of particles, but which are very small in size such that most will only be visible telescopically and will not be visible to the naked eye. As Asher's website notes, "Meteors in the outburst are expected to be quite faint, as in 1969; this makes it even more important than usual to be well away from artificial light pollution." http://www.arm.ac.uk/leonid/2006/info2006.html More recently, well-known meteor shower forecasters Esko Lyytinen and Tom van Flandern have confirmed McNaught & Asher's initial time prediction for a peak around 4:45 UTC. See the IMO fall 2006 calendar for a further description. http://www.imo.net/calendar/2006/fall But because a two-revolution old stream can degrade in unexpected ways, the IMO is recommending that since "other possible maxima are not excluded . . . , and observers should be watching as often as conditions allow throughout the shower, in case something unexpected happens." The thinking that the particles in this year's Leonids will be smaller in size and the fact that Leo will be even lower above the horizon at 4:45 UTC in the midwest United States is probably the basis of S&T's statement that "[e]lsewhere on the continent [other than the east coast of the United States], zero Leonids will be visible . . ." Because of the uncertainty and nature of this year's Leonids, you might want to consider telescopic observing and, if possible, using a web cam to record observations of the center of the radiant field near RA 153degs and Dec +22. Further details on telescopic and photographic observing can be found at the IMO Website at http://www.imo.net/photo and http://www.imo.net/tele . In short, the Nov. 2006 Leonids are not expected to be a great year, but are probably still worth a look-see in the early morning hours to check for any unexpected activity. - Kurt ____________________________________________________________________________________ Cheap talk? Check out Yahoo! Messenger's low PC-to-Phone call rates. http://voice.yahoo.com