The Leonids are comprised of debris left behind by Comet 55P/Temple-Tuttle and are the fastest of any meteor shower, hitting our atmosphere at a blazing 44 miles per second. No Leonid has been known to reach the ground as a meteorite because they are completely annihilated upon entry. Leo, the constellation from where the meteors appear to radiate from is well above the eastern horizon around 3:00 am.
The Leonids are best observed between midnight and dawn when an observer can spot 15-20 very fast meteors at peak during a normal year (more on this later). Most of the Leonids appear green or blue in color, are noted for producing fireballs, and about half of them leave trains of dust which can persist for minutes. As the night wears on, continue to follow Leo as he rises higher and higher into the sky. By 5:30 am this constellation will be high in the south-southeast sky.
While the Leonid meteor shower produces fairly low numbers of meteors during normal peak years, it is famous for producing “storm” level numbers reaching into the hundreds to a couple of thousand meteors per hour at peak. These storm levels occur about every 33 years when the Earth passes through one of the denser meteor streams associated with Comet 55P/Temple-Tuttle. The last incredible display occurred back in 2001 when hundreds of meteors were blazing across the sky before dawn.
This brief 2001 Leonids observing report was written by Skyscrapers’ Historian David A. Huestis:
For a couple of hours after midnight we were experiencing about 200 meteors per hour. Between 2:45 am and 3:45 am I personally counted 120. Oh well, you can't cover the entire sky! Then just after 4:00 am the rate started to increase and soon, between 4:30 and 5:30 am, the rate fluctuated between 600 and 800 per hour.
In one instance I saw 5 or 6 meteors radiate simultaneously from the radiate point in Leo. When I did a 360 degree look around, I often saw 3 or 4 meteors in the sky at once. Most left persistent trains of dust. There were quite a few fireballs as well. One in Orion left a dust train that lasted 5 to 6 minutes.
Buck Hill, Pascoag, Rhode Island
Unfortunately we’ll have to wait until 2031 to 2033 for the next major storm. And in fact, due to a variety of circumstances, the Earth may not encounter another Leonid "storm" until the year 2098 or even 2131.