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
, 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
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
. 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
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