Southern Sky Watch

Personal observations of the Leonids

My observations of the Leonids, converted to ZHR rates ASV group data Preliminary IMO data, both US and Australian Asian Peaks are higher, but I got the latest data sets too late to put up here.
I traveled to Alice Springs, almost slap bang in the middle of Australia, for my Leonids experience. I joined up with observers from the Eastern Australian Meteor Network and the Astronomical Society of Victoria to observe this event.

On Sunday there was much discussion of weather forecasts and fretting as to whether to stay in Alice Springs or head to Tennant Creek depending on forecast rain. As the day drew on, the skies stayed clear and forecasts suggested they would remain that way. My Leonid watch began somewhat early, as around 9.00 pm ACST I was telescopicaly observing the earth-lit dark face of the moon to see if I cool pick up any Lunar Leonid impacts. I didn't see anything, although US observers did pick up at least one confirmed Leonid to date (see links).

Around about midnight we went out to the Alice Springs Gliding Club, about 20 Km north of Alice Springs. Also at the site were some people form JPL, NASA and the Alice Springs Astronomical Society. While waiting for Leonids, we observed some faint galaxies, Saturn, Jupiter and comet LINEAR WM1 courtesy of Paul M and his 12" Dobsoinian (I am a convert to Dobsonians). In the clear desert air these were spectacular. While we waited we speculated on whether the weather would hold, if the predictions would turn out correct, and when we would see our first Leonid.

Our first genuine Leonid screamed up from the horizon like a rocket at approximately 1.30 am ACST (about 15.00 hrs UT Nov 18), followed rapidly by a second one. From then on the meteors kept coming rapidly. Initially there were several very bright blue ones that went across most of the sky, as well as quite a few that scooted along the edge of the horizon. The meteors were greeted with cheers and gasps of delight. I had rather imagined that the meteors would be roughly confined to a reasonable distance from the radiant, but in fact the meteors could start their "burn" overhead, to the north or to the south. People would yell out the direction of the meteors they saw and the Alice Springs nigh echoed with cries of "North!" "South!" "North-West" "Horizon" and cheers as another magnificent meteor shot across the sky.

There were small orange ones, green ones, white ones bright bright blue ones, several that were well over mag -4 (brighter than Venus) and at least one -10 (MUCH brighter than Venus). At the peak they were everywhere, ones shot through Orion and Taurus, below Jupiter and between Castor and Pollux, past the Southern Cross and past the Mangelanic clouds. Between two to four meteors would come past simultaneously. Some had small trails that faded quickly, others had long trails that faded slowly. I had come prepared to do some really serious Meteor counting, but brought the wrong cassette player, I bought the "play-only" one, not the recording one. So I was forced to use paper and pen, not a bad trick when trying to keep your eyes on the sky and write in the dark. At 3.30-3.45 am ACST (about 4.30 am AESDT and about 18.00 hr UT) I had a raw rate of ~1,000 per hour, and I know I was missing at least half. This probably explains why I don't see a clear peak like the ASV observers who were using tape recorders. The ASV people have estimated about 3,000-4,000 meteors at that time (see image above) meteors per hour for that time period. The IMO, averaging a large number of observations from different sites, put the figure at around 3,000 per hour.

Even when twilight came it didn't stop. As the sky lightened we could still see meteors shooting across the sky. One fanatstic one burst in a spectacular glare of light just above the dawn horizon. Even when the brightening sky was bereft of all but the brightest stars bright bolides punctuated the sky! I was ecstatic.

I returned back to the Caravan Park tired but happy, having seen a truly once in a lifetime event. Then began the long task of summarizing the data, and submitting it. This process is still on-going, but it looks as if the Asher/McNaught/Lyytinen/Flanders model is more correct than the Jenniskens model, and the Brown/Cooke model is clearly wrong. Whether the Asher/McNaught or Lyytinen model is closer well depend on more through analysis, but it looks as if meteor prediction is now a science, and not a dark art.

Links: (hopefully I will have my pictures developed soon)
Return to Leonids home page Return to Southern Sky Watch

Link to the Lab's 'In Space' section Link to the Lab's home page

This page is provided by Ian Musgrave and is © copyright 2001 Ian Musgrave, except the "Southern Sky Watch" logo, as well as any other ABC logo used on this page, is © copyright of the ABC. Sky maps are generated with SkyMap Pro 6.0

This page can be used freely for any non-commercial purpose but please attribute it correctly. However, see the disclaimer.

Email: reynella@mira.net e-mail Ian with any suggestions
Created: Tuesday, 27 November 2001, 11:22:13 PM
Last Updated: Tuesday, 27 November 2001, 11:30:13 PM