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 December 28, 1998:
If you're the type of person who enjoys a bit of arctic chill on a
moonlit winter night, then the 1999 Quadrantid meteor shower could be for
you.
Right: Artist Duane Hilton's concept of a Quadrantid fireball streaking through the moonlit sky above the White Mountain Range in central California. The shower stretches from Dec. 28, 1998 to Jan. 7, 1999, with a sharp maximum on Jan. 3 when as many as 100 shooting stars per hour are expected. The nearly full moon during the shower's peak will make most meteors difficult to see, but shooting stars brighter than magnitude 3 should be visible if the moon is the only source of light pollution. CLICK HERE! Despite the fact that the Quadrantids make up one of the year's most intense meteor showers, they are also among the least observed. Why? One reason is the weather. The shower's radiant is located high in the Northern sky, so the Quadrantids are visible mainly to observers in the Northern hemisphere where the weather is cold and often stormy in January. After a series of autumnal and early winter meteor showers like the Giacobinids, Leonids, and Geminids, many sky watchers have seen plenty of meteors by the time the Quadrantids arrive. Who can blame them for lingering by the comforts of the hearth while the shower rages outside? 
Left: Quadrantids observed in 1995
by members of the International Meteor Organization. More information.
The situation is almost certainly exacerbated by the brevity of the shower's peak, which usually lasts just a few hours. Even dedicated meteor observers are likely to miss such a sharp maximum simply because they live at the wrong longitude. In his classic book Meteor Astronomy, Prof. A.C.B. Lovell lamented that "useful counts of the Quadrantid rate were made in 24 Januaries out of a possible 68 between 1860 and 1927. ... The maximum rate during this period appears to have occurred in 1932 (80 per hour) although the results are influenced by unfavorable weather." |
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With observations in such short supply, it's no wonder that many
basic questions about the Quadrantids remain unanswered. For example,
What is the source of the Quadrantid meteors? No one knows.
Most meteor showers are caused by comets. When a comet passes close to the sun, bits of dust and ice boil away from its nucleus and form a stream of tiny particles, called meteoroids, that orbit the sun. A meteor shower results when Earth passes through the debris stream. |
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Presumably the Quadrantid meteors are formed in the same way.
But when astronomers compare the orbits of Quadrantid meteoroids with the
orbits of all known comets and asteroids, they can't find a match.
The source of the Quadrantid meteor shower is unknown.
Quadrantid meteroids are in a highly elliptical orbit tilted about 70 degrees from the plane of the solar system. Some astronomers have speculated that the parent comet was captured or disrupted by Jupiter's gravity thousands of years ago, and that the Quadrantid meteoroids are the leftovers from that ancient celestial collision. Advocates of this idea believe that the original comet was orbiting the Sun nearly in the plane of the solar system. Since its disruption, the orbit of the debris stream evolved to its present state because of periodic gravitational perturbations from Jupiter. Other scientists argue that the source of the Quadrantids could be an existing comet or asteroid that has yet to be discovered. If this is true, then we might expect to see outbursts of Quadrantid meteors during years when the parent comet is nearby, just as the well-known Leonid meteors are especially intense around the time that their parent comet, Tempel-Tuttle, passes close to Earth. In this regard, amateur observations of the Quadrantids could prove especially valuable to professional astronomers who would like to know when to look for the source of the meteors. |
The NASA Star Trails Society invites you to observe the Quadrantids
and to submit your observations for analysis by
scientists studying the meteor shower.
Star Trails
is
part of the NASA/Marshall Space Science Lab's
"Partners in
Discovery" initiative to involve
our readers in scientific research.
Several times each month we
announce opportunities for
amateur scientists to contribute
to research in astronomy,
astrobiology, and other natural
sciences. For more information
about observing the Quadrantids or
to become a member please visit
www.StarTrails.com.
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at a Glance
 |
Normally the best time to view a meteor shower is between 2 a.m. and dawn. That's when
the local sky is pointing directly into the meteor stream.
This year's Quadrantids will be an exception to this rule, thanks to the
full moon. When the shower peaks on the evening of
January 3, the face of the moon
will be 96% illuminated, rendering all but the brightest
meteors invisible. Shooting stars brighter than magnitude 3 should be
visible in locations where the only significant source of light pollution
is the moon. As usual, the best time to observe is between 2 a.m. and dawn
when the rate of meteor activity is greatest.
You won't need binoculars or a telescope to view the Quadrantids. The naked eye is usually best for seeing meteors which often streak more than 45 degrees across the sky. The field of view of most binoculars and telescopes is simply too narrow for good meteor observations. 
Experienced meteor observers suggest the following viewing strategy:
Dress warmly. Bring
a reclining chair, or spread a thick blanket over a flat spot
of ground. Lie down and look up somewhat toward the north. Meteors can appear in any part of the sky, although their trails will
tend to point back toward the radiant (see the sky map below). |
The image indicates the general region of the sky from which the Quadrantid meteors appear to emanate (red dot). This point, called the radiant, is really an optical illusion - the meteors are moving along parallel paths, but appear to come from a single point, just as a stretch of parallel railroad tracks will appear to meet at a point on the horizon. Most meteor showers are named after the constellation of the radiant. The Quadrantids take their name from an obsolete constellation called Quadrans Muralis found in early 19th-century star atlases between Draco, Hercules, and Bootes. |
| Web Links | |
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The Star Trails Society -- Join
NASA as a Partner in Discovery!
NASA Liftoff meteor shower pages - learn the basics about meteor showers. Includes tutorials, Java animations, and educational activities. Satellite Tracking - monitor satellites as they weather the meteor shower NASA's Office of Space Science - press releases and other news related to NASA and astrophysics External Links: The Quadrantids -- from Gary Kronk Meteors and Comets web site North American Meteor Society -- Observing Guide |
Related Stories: 22 Dec. 1998: The Ghost of Fireballs Past -- RADAR echoes from Leonid and Geminid meteors.15 Dec. 1998: Bunches & Bunches of Geminids -- the Geminids continued to intensify in 1998 27 Nov. 1998: The 1998 Leonids: A bust or a blast? -- New images of Leonid fireballs and their smokey remnants. 23 Nov. 1998: Leonids Sample Return payload recovered! -- Scientists are scanning the "comet catcher" for signs of Leonid meteoroids. 19 Nov. 1998: Early birds catch the Leonids -- The peak of the Leonid meteor shower happened more than 14 hours earlier than experts had predicted. 18 Nov. 1998: A high-altitude look at the Leonids -- NASA science balloon catches video of 8 fireballs. 16 Nov. 1998: The Leonid Sample Return Mission -- NASA scientists hope to capture a Leonid meteoroid and return it to Earth. 10 Nov. 1998: Great Expectations: the 1998 Leonid meteor shower -- the basics of what the Leonids are and what might happen on November 17. |
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return to Space Science News Home Author: Dr.
Tony Phillips |
