If predictions by the world’s top meteor experts hold up, early on the
morning of November 18th skywatchers in North America can expect to see their
most dramatic meteor shower in 35 years. These meteors, called Leonids because
they appear to radiate from the constellation Leo (the Lion), will signal the
collision of Earth with streams of fast-moving dust particles shed by Comet
Tempel-Tuttle.
In the November 2001 Sky & Telescope — the magazine’s 60th-anniversary
issue — meteorologist Joe Rao assesses the predictions provided by three
teams of specialists. Rao concludes that two dramatic displays called “meteor
storms” appear likely.
A burst lasting perhaps two hours is expected in the predawn hours of November
18th for observers throughout most of North and Central America. The maximum
rates should occur at 5:00 a.m. EST (corresponding to 4:00 a.m. CST, 3:00 a.m.
MST, 2:00 a.m. PST). With no moonlight spoiling the view, the storm may
briefly generate anywhere from several hundred to 1,000 or 2,000 meteors per
hour for observers with clear, dark skies.
An even bigger storm arrives 8 hours later for viewers rimming the far-western
Pacific Ocean. Because these locations are on the other side of the
International Date Line, this peak occurs before dawn on November 19th.
Several thousand meteors may streak across the sky for an hour or so starting
at 3:30 or 4:30 a.m. in eastern Australia (depending on location); 2:30 a.m.
in Japan; and 1:30 a.m. in western Australia, the Philippines, and eastern
China.
Meteors create momentary “shooting stars” when flecks of interplanetary dust
strike Earth’s atmosphere at high speed. The Leonids, which are one of a
dozen or so annual meteor showers caused by cometary dust, arrive at a
blistering 44 miles (71 kilometers) per second — the fastest known. Typically
showers produce one meteor every few minutes, though often there are bursts
and lulls. Two years ago the Leonids briefly peppered the skies over Europe
and the Middle East with up to 2,500 meteors per hour. In 1966 lucky observers
in the southwestern United States gaped in awe for 20 minutes as Leonid
meteors fell at the rate of 40 per second!
More about the prospects for a Leonid storm appears in the November issue of
Sky & Telescope. This issue marks the diamond anniversary of the monthly
magazine for amateur astronomers launched by Charles and Helen Federer in
November 1941. The Federers took on the challenge of merging The Sky (which
had been published by New York’s Hayden Planetarium) and The Telescope (then
published by Harvard College Observatory). Today the magazine is enjoyed by
some 250,000 skywatchers worldwide.
Sky & Telescope will issue another press release closer to the date of the
Leonid meteor shower containing background information about meteors and
how to observe them. More information is already available on the magazine’s
Web site at:
http://www.skypub.com/sights/meteors/meteors.html