LEONID DAILY NEWS: November 19, 2002
Figure 1: Summary of 2002 Leonid storm counts .
LEONID STORMS RICH IN FAINT METEORS
The two anticipated Leonid meteor storms occurred much as predicted. European
observers saw the peak at 04:09 UT (ZHR = 2,300/hr), while observers in the
America's witnessed a storm peaking at 10:50 UT (ZHR = 2,600/hr). Both peaks
were narrow, with a full-width-at-half-maximum of only 0.52 and 0.50 hours,
respectively. Both peaks were also rich in faint meteors. As a result, the near-full
Moon and bad weather at prime observing sites made visual observations from the ground
difficult. Nonetheless, viewing from the airborne platforms was spectacular. The
graphs above show the preliminary results from 1-minute counts gathered by
Morris Jones
and seven other members of the flux measurement team on board
NASA's DC-8
Airborne Laboratory during the 2002 Leonid MAC mission,
as compared to visual observations gathered by the
International Meteor Organization .
The new observations provide important new data for dust
trail models. The dynamic models by Esko
Lyytinen et al. and Jeremie Vaubaillon
were only minutes off from the
observed peak time. The narrow flux profiles demonstrate that the dust trail does not widen
over time, as in the models by
Lyytinen et al.,
Asher and McNaught, and Vaubaillon.
The measured width
is only slightly narrower than predicted by Jenniskens [PDF file
] (0.64 and 0.60 hr, respectively).
In addition, the strong showing in Europe confirms the small trail shifts noticed earlier.
The most important result may have been the abundance of
faint meteors. While predicted in some models, such as that of
Jenniskens, the
distribution of meteoroid sizes in dust trails is not yet understood.
A high background of activity persisted between the two storm peaks. That background
may reflect the 1833 dust trail encounter (Lyytinen's prediction
put the encounter time at 06:36 UT), or it could be a manifestation of the Leonid Filament.
Previous news items:
2002:
Nov 19 - Leonid storms rich in faint meteors
Oct 22 - Collecting meteoroid debris from snow cover
Oct 21 - Highlights COSPAR/World Space Congress
Aug 31 - First UV spectrum: Leonid from space
2001:
Dec 11 - Shocking Leonid
Dec 01 - Moon impacts
Nov 26 - Near-IR persistent train emission
Nov 24 - Results of near-real time flux measurements
Nov 22 - Wowh! Optical meteor spectra
2000:
Dec. 25 - Ursid shower circular IMO
Dec. 24 - Ursid shows early release of sodium
Dec. 23 - Ursid outburst confirmed
Dec. 18 - Dec 22 Ursid outburst
Nov. 20 - A bacterial fingerprint?
Nov. 15 - HCN disappears mysteriously
Nov. 14 - Meteor shower from space
Nov. 13 - Organic fingerprint
Nov. 12 - Train airglow chemistry
Nov. 11 - Hard bits and persisting glows
Nov. 10 - Meteoroid debris detected
Nov. 09 - New meteor picture
Nov. 08 - Spin city
Nov. 07 - Meteors affect atmospheric chemistry
Nov. 06 - Listen to this!
Nov. 04 - Fear of heights?
Nov. 03 - The pale (infra-red) dot
Nov. 02 - Twin showers
Nov. 01 - Leonids approaching Earth
Oct. 31 - Prospects for Moon Impact Studies
Oct. 30 - Comet dust crumbled less fine
Today's news
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Results of this research were published in Meteor Showers and their Parent Comets (Cambridge University Press).
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