Dec 28, 2000

Millennium Meteors




North Americans will have a front-row seat for a brief but powerful meteor shower on January 3, 2001.
December 29, 2000 -- One of the most intense annual meteor showers, the Quadrantids, will peak over North America on January 3, 2001. Observers in western parts of Canada, the USA and Mexico could see an impressive outburst of shooting stars, numbering as many as 100 per hour.


Forecasters expect the shower to climax during a two hour interval around 1200 Universal Time on January 3rd. That's 7 o'clock Wednesday morning in the Eastern Standard time zone or 4 o'clock Pacific Standard time.

Above: Quadrantid meteors captured on video in 1995 by members of the International Meteor Organization. [more information]

"The east coast of North America will be in bright morning twilight [when the shower peaks]. Sky watchers there may miss the very best rates," says Robert Lunsford, Secretary General of the International Meteor Organization. "Easterners could still see an impressive display just before the onset of morning twilight, but observers located in the Midwest and onward toward the Pacific will have a better chance to witness maximum activity."




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"This is the best chance for North American observers to see this shower until the year 2009," he added.

To view the Quadrantids, simply go outside an hour or so before the expected maximum and face north. The shower's radiant (a point in the sky from which meteors appear to stream) will lie about 35 degrees above the northeastern horizon in the constellation Bootes. Quadrantid meteors can appear anywhere in the heavens, but their trails will point back toward the radiant.

"The advantage of setting up early is that you could see a trickle of activity turn into a torrent of meteors," said Lunsford. "The longer you watch the more likely you are to witness a Quadrantid fireball, a meteor [at least as bright as] the planet Venus. My brightest Quadrantid was in 1981 when I saw a -10th magnitude fireball shoot high into the eastern sky. It cast shadows and left a 4-minute persistent train."

Although the Quadrantids are among the most active of all regular meteor showers, they are seldom widely observed. The northern radiant favors observers where January weather is often cold and stormy. With a maximum that lasts just two hours, the elusive Quadrantids are easily spoiled by a good winter storm.


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Above: The northern sky on Jan. 3, 2001 at 4 a.m. local time as viewed by an observer at mid-Northern latitudes. The red dot is the Quadrantid radiant.

Quadrantid meteors take their name from an obsolete constellation, Quadrans Muralis, found in early 19th-century star atlases between Draco, Hercules, and Bootes. It was removed, along with a few other constellations, from crowded sky maps in 1922 when the International Astronomical Union adopted the modern list of 88 officially-recognized constellations. The Quadrantids, which were "re-zoned" to Bootes after Quadrans Muralis disappeared, nevertheless retained their name -- possibly because another January shower was already widely-known to meteor watchers as the "Bootids."

Quadrans Muralis isn't the only thing about the Quadrantids that's extinct. The parent of the shower might itself be long-dead.


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Like all meteor showers, Quadrantid outbursts happen when Earth passes through a stream of dusty debris from a comet or, more rarely, an asteroid. Every major meteor shower has a well-known parent -- except the Quadrantids. Astronomers have looked for a comet that shares the orbit of the Quadrantid debris stream but, so far, they've found nothing.

The Quadrantid comet might have disintegrated long ago, as did comet C/1999 S4 (LINEAR) earlier this year following a close encounter with the Sun. Or perhaps the source of the Quadrantids is simply defunct -- a dull, hard-to-see comet that long ago exhausted its store of volatile ices. No one knows.

Above: The Hubble Space Telescope captured this image of comet LINEAR disintegrating in August, 2000. [more information]

But one thing is clear: the Quadrantids are coming and they'll be here next week. The first quarter Moon will sink below the horizon near midnight on January 3rd, affording dark skies for meteor watchers on Wednesday morning. With just a little cooperation from Old Man Winter, North Americans could enjoy a dazzling sky show to begin the new millennium.

Tune in to for updates and images of the Quadrantid meteor shower.


Web Links


Learn more about the Quadrantids -- compiled by Gary Kronk


The shower is active from Dec. 28 until Jan. 7, but the pre-dawn hours of Jan. 3 should be the best time to watch.

The radiant is in the constellation Bootes at RA=15h20m, DEC=+49o.

Quadrantid meteoroids hit the atmosphere travelling at about 41 km/s.


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