The Leonid Meteors 2003

The Leonids are the debris of Comet 55P/Tempel-Tuttle. Every 33 years or so, the comet returns to the inner solar system and releases material that forms into a new dust trail. The Earth's passage right through the centre of trails is associated with the most spectacular meteor displays (studies show that, as well as how close to the centre of the trail you are, the strength of the display also depends on how far along a trail's length you are). For example, in 2001 November and again in 2002 November, the Earth passed very near the centre of the trail released at the 1866 return (i.e. 4 revolutions of the comet ago), as well as near other trails, producing meteor storms. The following diagram shows the position of the 6 youngest Leonid dust trails when the Earth traverses the Leonid stream in 2003 November. Unfortunately the Earth does not have a close encounter with any of these trails.
Further explanation of this plot is available.
However, a recent paper by Vaubaillon et al. shows that the Earth will encounter older material released from Tempel-Tuttle, leading to enhanced meteor activity (below storm level), at various times. Meteors from the 1499 trail will be visible on November 13th. The peak ZHR (Zenithal Hourly Rate = number of meteors visible to someone who has perfect observing conditions; real rates are usually somewhat smaller) is estimated as 100, but there should be some activity lasting for hours, even up to half a day. The best time is roughly between 13:00 and 19:00 UT (Universal Time = Greenwich Mean Time), favouring Pacific and east Asian regions, which have the second half of the night (when Leonids are visible) at that time. In east Asia, this is the early hours of November 14th local time. The 1533 trail will produce activity with a maximum (possibly reaching a ZHR level of 100) around November 19th, 06:30 to 08:00 UT. This timing favours Atlantic and east American regions. The Earth will encounter the 1333 trail producing a maximum around November 20th, 01:00 UT (favouring Europe and the near/Middle East) but the peak ZHR is estimated at only 20 or so. At least the meteors may be a bit brighter than for the 1499 and 1533 trails. Further details, including other minor enhancements, are given in the paper. Note the update, not provided in the paper, giving a maximum of ZHR=70 at November 19th, 16:50 UT (west Pacific and east Asia), due to the 1733 trail, but remember that this prediction is quite model dependent. Apart from these encounters with old Leonid trails, there is a background to the Leonid shower for more than a week, at rather low rates (e.g. ZHR of 10 or so). The most enthusiastic observers may therefore like to observe on clear nights from November 13th to 23rd, from when Leo rises, in the middle of the night, until morning twilight. The lunar phase is unfavourable near the start of this period (full on 9th), becoming less bad as the days progress. A few other links (on 2003 predictions, observing tips, etc.): Armagh press release
IMCCE 2003 predictions
Celestial Delights - After the Storms
Science@NASA, 2003 Leonids
Leonid MAC - Current Meteor Storm Predictions
Leonid MAC homepage
International Meteor Organization

Last Revised: 2009 November 10th