November 17 - 18, 2001: Leonid Meteor Shower

One of many trip reports by Alan Silverstein.
Last update: May 6, 2008

The following two items were originally posted by me to an HP-internal newsgroup, before and then after the event; later edited into past tense, etc.


...The Sky & Telescope newsletter contained a specific prediction: The peak was to be one half hour centered on 3:09 am MST; up to 2000 ZHR (Zenithal Hourly Rate, the number you might see under perfect conditions if the radiant was overhead).

This was just one of four predictions, which varied, but it appeared to be the most specific. Over the last few years the cycle of Leonids peaking allowed theorists to refine their predictions to an astonishing degree. They were nailing specific threads of particles emitted by the comet in specific years. However, there were still uncertainties about orbital perturbations, hence varying predictions.

Based on my experience several years ago, you'd want to be in position as soon as Leo rises, which is about 11:30 pm if I recall right. At this time the meteors were streaking across the entire sky about one per minute. Later they were brighter but shorter.

...Now, where to go? Somewhere as clear, dark, and warm as possible with a good view especially northeast. So, not the mountains, but east. I considered Pawnee Buttes myself, but it got reasonably dark about when you crossed the Weld County line. There were some county roads suitably far from any farmhouse lights, and on top of a hill. A few years ago I waypointed this location: 40 37'31.0" -104 53'44.1"


...I went to my "dark" location (previously posted). I was there from about 11:45 pm to 5:00 am. At first it was 80% cloudy and the rest was hazy, but it cleared up completely by about 2:30 except for a bit of light pollution from the obvious glows of Cheyenne to the north, FC/Loveland west, and Greeley south. The Milky Way was clearly visible, although dim compared to truly dark skies. The location was not on top of a hill as I recalled, actually down low, but this blocked most lights in the distance. (And cell phone coverage, but not ham radio.)

I thought I would have trouble staying awake, but after turning on the ham radio and chatting with others out meteor hunting, I was actually pretty busy. People were out searching for clear skies. I started to see stars to the horizon to the NW, and sure enough the clouds blew away or dissipated. I saw a couple of bright meteors through the clouds while getting settled and mucking with the radio.

Initially Leonid meteors were frequent, but not remarkably so. I was warm enough as long as I stayed in my sleeping bag. At 2:00 am a car came down my dead-end county road and scared the @_#$!$ out of me, but it turned out to be the Christofanelli family using my GPS coordinates (grin). Between 1 am and 2 am (I think), I did a couple of 10-minute counts without serious concentration, and got 6-7 "definite Leonids" each time; definite meaning I was certain of identity, and that I had seen something for sure. Meteors being all over the sky, this involved a lot of fast head-turning.

Things got exciting at about 2:40. I did a more focused 10-minute count and got 33 meteors, a rate of at least 200/hour, not even correcting for limiting magnitude, sub-zenith altitude of Leo, or peripheral vision loss due to glasses. This was exciting with the predicted peak just a quarter hour away, and it was already a high rate. I turned on the car hi fi, opened the doors wide, and we listened to Science Fiction Movie Classics.

It never quite rained meteors, but it was still the densest shower I had ever seen by far, including the Leonids 2-3 years ago. By the predicted peak at 3:06, they came in bursts too frequent to keep up counting! I would guess ZHR of at least 1000, maybe 5000, it probably did average over 1/second.

I was quite "jazzed" (grin). I got up many times to roam down the road to talk with the Christofanellis, who were bedded down by their SUV. It was comfortably warm in my sleeping bag, but outside I'd start shivering soon despite being dressed warmly. Frost formed on the bag.

Walking on the road and turning circles, it seemed there were meteors all over the sky. I didn't have to wait long, a few seconds, to see one wherever I happened to look. Closer to Leo, as it rose, there were short, bright "point meteors" and short streaks. Low to the horizon were occasional bright flashes through ground haze. Perhaps 10 times that night there was a flash like lightning, and a glowing contrail that lasted for several minutes. The single brightest meteor I saw was a definite blue color, and probably brighter than magnitude 0.

I planned to head home after 3:30 or so, but the show was so amazing and unusual that I stayed until it started to get light in the east. It didn't really taper off either. There were many "bursts" of perhaps dozens of meteors in 10-20 seconds, and then lulls. There were many cases of 2-4 meteors appearing nearly simultaneously, and some definite parallel streaks. Meteors came frequently enough that you could visually pin down the radiant to within half a degree or so (full moon size).

I also saw perhaps five "sporadic" (non-Leonid) meteors.

Driving back to Fort Collins took 25 minutes. During that time I saw two more bright meteors streaking down west, toward the mountains. Back at home, before going to bed at about 5:30, I saw a couple more in the sky in just a couple of minutes.

I've heard from lots of people that forgot or thought it was cloudy. My cell phone was out of range down in a "hole", and I made limited local calls on my ham radio. I wish I'd brought an address book and woken up everyone I know (grin).


From:  "John Wagoner" <stargate@astromax.com>
Date:  24 Nov 2001 16:47:24 -0700
Subject:  [skyline]  S&T's News Bulletin for November 23, 2001
To:  <skyline@astromax.com>

...

LEONID METEORS ROAR IN ON SCHEDULE

The best meteor shower in 35 years sent bright shooting stars streaking through the sky before dawn Sunday morning for observers throughout the Americas, the Pacific, and the Far East. Preliminary reports paint a picture of the much-anticipated 2001 Leonid shower matching predictions fairly closely. However, the observed rates of a couple of thousand per hour (as seen by a single observer) fell shy of the most optimistic predictions of between 7,000 and 15,000 per hour.

In eastern North America, skywatchers under dark skies before dawn counted several hundred meteors per hour -- an average of one every 5 or 10 seconds, with occasional spectacular bursts (presumably by chance) of two or three at once. A crowd of SKY & TELESCOPE staffers at a lakeshore in western Massachusetts (under a 6th-magnitude sky) oohed and aahed at blue, green, and red fireballs radiating from the cutting edge of the Sickle of Leo, occasionally lighting the ground with flashes like distant heat lightning. The peak for North America was predicted to arrive around 10:00 Universal Time (shortly before dawn in the East), but rates seemed still to be increasing as morning brightened the sky.

Indeed, observers farther west reported an even more spectacular show a little later. In Kentucky, David Phillips described seeing roughly a meteor per second under an extremely dark sky. Much of the Midwest was cloudy, but Westerners apparently had the best of it. The peak probably came around 11:00 UT, according to Joe Rao, observing with a crowd of 60 at the Skywatcher's Inn in Arizona. "It was partly cloudy here, with 30 to 70 percent sky obstruction, but you couldn't look up for more than a second or two without seeing a meteor, sometimes four at once," said Rao. "These were 1st and 2nd magnitude. It was the most amazing shower I've seen in over 35 years of watching the sky."

Observing from Fremont Peak, California, Landon Curt Noll observed several bursts of activity including a count of more than 1,500 meteors during a 1-hour interval beginning at 10:45 UT, with more than 600 of those appeared in the 15 minutes beginning at 11:00.

Rates seemed to decline somewhat after about 11:15 UT, but farther west in Hawaii, Stephen J. O'Meara and P. K. Chen were more than satisfied as the radiant rose high in the sky from about 12:00 to 16:00 UT. "We had an absolutely stunning, remarkable, brilliant and continuous display of Leonids," writes O'Meara. "The best activity I have ever seen. Though there was no 'storm' -- meaning the sky was not filled with meteors falling down like rain -- the shower did rain meteors and fireballs for four hours."

The biggest peak was predicted to arrive around 18:00 UT, when Australia and the Far East would be turned into view. Rates did surge again around this time, but judging from early reports, this second peak was only comparable to the first. According to early reports from the International Meteor Organization, "The strongest peak observed [was] around 18:20 UT.... The rates during this peak reached more then 2800 meteors per hour." Observing from Alice Springs, Australia, Bradley Schaefer reported a personal meteor count that peaked with 660 meteors seen during a 15-minute interval. "They were fast," he writes, "and the bright ones were visible in various colors, primarily red, green, and yellow." ...