[meteorite-list] Fireball Sightings (Taurids Meteor Shower)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Nov 3 18:16:58 2005
Message-ID: <200511032315.jA3NFZT04176_at_zagami.jpl.nasa.gov>

http://science.nasa.gov/headlines/y2005/03nov_taurids.htm

Fireball Sightings
NASA Science News
November 3, 2005

Earth is orbiting through a swarm of space debris that may be producing
an unusual number of nighttime fireballs.


November 3, 2005: "I thought some wise guy was shining a spotlight at
me," says Josh Bowers of New Germany, Pennsylvania. "Then I realized
what it was: a fireball in the southern sky. I was doing some backyard
astronomy around 9 p.m. on Halloween (Oct. 31, 2005), and this meteor
was so bright it made me lose my night vision."

Bowers wasn't the only one who saw the fireball. Lots of people were
outdoors Trick or Treating. They saw what Bowers saw ... and more.
Before the night was over, reports of meteors "brighter than a full
moon" were streaming in from coast to coast.

Astronomers have taken to calling these the "Halloween fireballs." But
there's more to it than Halloween. The display has been going on for days.

On Oct. 30, for example, Bill Plaskon of Jonesport, Maine, was
"observing Mars through a 10-inch telescope at 10:04 p.m. EST when a
brilliant fireball lit up the sky and left a short corkscrew-like smoke
trail that lasted about 1 minute."

On Oct 28, Lance Taylor of Edmonton, Alberta, woke up early to go
fishing with five friends. At about 6 a.m. they "noticed a nice
fireball. Then 20 minutes later there was another," he says.

On Nov. 2 in the Netherlands, "The sky lit up very bright," reports Koen
Miskotte. "In the corner of my eye I saw a fireball about as bright [as
a crescent moon]."

And so on...

What's happening? "People are probably seeing the Taurid meteor shower,"
says meteor expert David Asher of the Armagh Observatory in Northern
Ireland.

Every year in late October and early November, he explains, Earth passes
through a river of space dust associated with Comet Encke. Tiny grains
hit our atmosphere at 65,000 mph. At that speed, even a tiny smidgen of
dust makes a vivid streak of light--a meteor--when it disintegrates.
Because these meteors shoot out of the constellation Taurus, they're
called Taurids.

Most years the shower is weak, producing no more than five rather dim
meteors every hour. But occasionally, the Taurids put on quite a show.
Fireballs streak across the sky, ruining night vision and interrupting
fishing trips.

Asher thinks 2005 could be such a year.

According to Asher, the fireballs come from a swarm of particles bigger
than the usual dust grains. "They're about the size of pebbles or small
stones," he says. (It may seem unbelievable that a pebble can produce a
fireball as bright as the Moon, but remember, these things hit the
atmosphere at very high speed.) The rocky swarm moves within the greater
Taurid dust stream, sometimes hitting Earth, sometimes not.

"In the early 1990s, when Victor Clube was supervising my PhD work on
Taurids," recalls Asher, "we came up with this model of a swarm within
the Taurid stream to explain enhanced numbers of bright Taurid meteors
being observed in particular years." They listed "swarm years" in a 1993
paper
<http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1993QJRAS..34..481A>
in the Quarterly Journal of the Royal Astronomical Society and predicted
an encounter in 2005.

It seems to be happening.

When should you look? You might see a fireball flitting across the sky
any time Taurus is above the horizon. At this time of year, the Bull
rises in the east at sunset. The odds of seeing a bright meteor improve
as the constellation climbs higher. By midnight, Taurus is nearly
overhead, so that is a particularly good time.

According to the International Meteor Organization, the Taurid shower
peaks between Nov. 5th and Nov. 12th (details
<http://www.imo.net/calendar/2005/fall>). "Earth takes a week or two to
traverse the swarm," notes Asher. "This comparatively long duration
means you don't get spectacular outbursts like a Leonid meteor storm."
It's more of a slow drizzle--"maybe one every few hours," says Asher.

A drizzle of fireballs, however, is nothing to sneeze at. So keep an eye
on the sky this month for Taurids.
Received on Thu 03 Nov 2005 06:15:35 PM PST