The Leonid Meteors

Predicting the most spectacular meteor storms is now a remarkably exact science, with some excellent Leonid displays happening in recent years, for observers in the right parts of the world. These predictions involve the accurate modelling of dust trails within the Leonid stream.

Leonids in 2010

Nothing spectacular is expected from the Leonids in 2010. Indeed, attention is turning instead to major outbursts in other showers, such as the 2011 Draconids.

For the 2010 Leonids, it is possible (see links below) that the peak ZHR (Zenithal Hourly Rate, the rate of meteors seen in idealised observing conditions) could reach as high as 20, which would be marginally more than in standard Leonid years. This peak will be around 15:00 UT on the 17th of November (Pacific longitudes best) with the traditional peak being around 21:00 UT that day (central to east Asian longitudes best).


IMO Meteor Shower Calendar
Maslov: Leonids 2010: prediction of activity
Maslov: Leonids 2009-2010, including Leonids 2010 overview
Maslov: parameters of Leonid trail encounters 2001-2010

Leonids in 2009

See also:
"Leonid Meteors Outburst" - press release
Movies of Leonid Meteors from night of 2009 November 16th - 17th
Leonids 2009: visual data quicklook
Jeremie Vaubaillon
Mikhail Maslov
Peter Jenniskens / Leonid MAC
IMO Meteor Shower Calendar

Although the 2009 shower will not produce the storm level activity of the Leonids some years ago, observers in the right part of the world should see some nice outburst level activity. This will be due to material released by the Leonid parent comet, 55P/Tempel-Tuttle, at various past returns, especially those in 1466 (16 revolutions ago) and 1533 (14 revolutions ago).

Here are some 2009 Leonid results we calculated with dust trail theory, i.e. following techniques pioneered by Kondrat'eva and Reznikov:

Trail Delta a_0 rE-rD AU f_M Time
14-rev +0.136 -0.0005 -0.09 Nov 17, 21:15 UT
16-rev +0.105 +0.0011 0.10 Nov 17, 21:20 UT
16-rev +0.106 +0.0009 -0.04 Nov 17, 22:00 UT

- notation explained in Mc Naught and Asher's paper. A fuller list of trail encounters in 2009 is provided by Mikhail Maslov's comprehensive study.

In fact, the above trail encounter data should not be interpreted as having the same accuracy as data for very young trails, because these older trails have had more time for the meteoroids in them to become more scattered or disrupted. But the independent calculations of various researchers have confirmed that both these trails ARE encountered by the Earth in the late UT/GMT hours of Nov 17 (maybe extending to the very start of Nov 18 depending on duration). See especially the results of Jeremie Vaubaillon's computer models.

Mid-Asia is best placed to see the resulting outburst activity. Prakash Atreya, formerly of Armagh Observatory, is organising an international Leonid observation campaign in Nepal.

As the lunar phase - virtually new - is excellent for the 2009 Leonids, there should at least be a few Leonids to see wherever (clear and dark) you are, on nights near Nov 17. Leonid meteors are best seen in the second half of the night (exactly how many potential observing hours you get depends on your latitude).

1833 Meteor Storm
Engraving of 1833 meteor storm
(Made some decades later)

Earth day/night + Leonid diagram


Prospects for November 2007
Forecast for 2007 from the IMCCE (Jeremie Vaubaillon)
Forecast for 2007 from Mikhail Maslov


2006 Reports
Prospects for November 2006
Forecast for 2006 from the IMCCE
Forecast for 2006 from Mikhail Maslov
Forecast for 2006 from Mikiya Sato
McNaught/Asher estimates for years 2000 to 2006


Forecast for 2005 from the IMCCE


Prospects for November 2004
The unexpected 2004 Leonid meteor shower - PDF Format
2003 and 2004 from Leonid MAC


Predictions for 2003

Observation Reports for 2002

Dazzling Display -
UK Clouded Over - BBC
Images from
Radio Forward Scatter Observations, UK


"Leonid dust trail structure and predictions for 2002"
by R.H. McNaught and D.J. Asher
in PDF and Postscript formats.
Summary for 2002
Comparison of 2002 Predictions
Lyytinen's Predictions
Francis Reddy's Site
Gary Kronk Leonid page
Leonids 2002 at
NASA Forecasts
Warnings for Spacecraft
Astronomy Magazine
How to View Meteor Showers
Photographing Meteors


2001 Reports
2001 Reports from Italy
2001 Report by Daniel Fischer
Images of the storm
Predictions compared to observations
McNaught-Asher Predictions for 2001 News


Reports of 2000 Observationsfrom the IMO
Reports of 2000 Observations from the AMS
Reports of 2000 Observations from ESA
Leonid 2000 Radio Observations
Leonid 2000 Amateur Observations
Predictions for 2000


Reports of the 1999 Leonid Shower
Final Comments for 1999 from Asher and McNaught
Earth in a Twist: Predicting the Storm 1999


The 1998 Leonid fireball outburst

Other Leonid Sites

Leonid MAC - NASA Ames
Leonid Photos and Links from Timo Leponiemi
Leonid Site by Carl Koppeschaar
Near-Live Leonid Watching System
Ancient and Medieval Leonid Observations
Japan and the 1698 Leonids
International Meteor Organization

Biography of Wilhelm Tempel by J.L.E. Dreyer former Director of Armagh Observatory.

Last Revised: 2010 December 13th