[meteorite-list] The 2006 Geminid Meteor Shower

From: Gerald Flaherty <grf2_at_meteoritecentral.com>
Date: Wed, 13 Dec 2006 12:45:02 -0500
Message-ID: <003a01c71ede$6b330ff0$6402a8c0_at_Dell>

Cloudy with a chance of rain through tonight[_at_ noon today] too too bad.
PS I just got a celestron Skyscout. Should help with locating comets,
astroids, "Minor"[duh] planets and Uranus, Neptune and a host of deep sky
objects. Might even fill in all the Messier objects + some of the NGC's or
is it NCG's?? Tiny test shows potential!
Jerry Flaherty
----- Original Message -----
From: "Ron Baalke" <baalke at zagami.jpl.nasa.gov>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Sent: Tuesday, December 12, 2006 8:00 PM
Subject: [meteorite-list] The 2006 Geminid Meteor Shower


>
> http://science.nasa.gov/headlines/y2006/12dec_geminids.htm
>
> The 2006 Geminid Meteor Shower
> NASA Science News
> December 12, 2006
>
> Dec. 12 , 2006: The best meteor shower of the year peaks this week on
> Dec. 13th and 14th.
>
> "It's the Geminid meteor shower," says Bill Cooke of NASA's Meteoroid
> Environment Office in Huntsville, Alabama. "Start watching on Wednesday
> evening, Dec. 13th, around 9 p.m. local time," he advises. "The display
> will start small but grow in intensity as the night wears on. By Thursday
> morning, Dec. 14th, people in dark, rural areas could see one or two
> meteors every minute."
>
> The source of the Geminids is a mysterious object named 3200 Phaethon.
> "No one can decide what it is," says Cooke.
>
> The mystery, properly told, begins in the 19th century: Before the
> mid-1800s there were no Geminids, or at least not enough to attract
> attention. The first Geminids appeared suddenly in 1862, surprising
> onlookers who saw dozens of meteors shoot out of the constellation
> Gemini. (That's how the shower gets its name, the Geminids.)
>
> Astronomers immediately began looking for a comet. Meteor showers result
> from debris that boils off a comet when it passes close to the Sun. When
> Earth passes through the debris, we see a meteor shower.
>
> For more than a hundred years astronomers searched in vain for the
> parent comet. Finally, in 1983, NASA's Infra-Red Astronomy Satellite
> (IRAS) spotted something. It was several kilometers wide and moved in
> about the same orbit as the Geminid meteoroids. Scientists named it 3200
> Phaethon.
>
> Just one problem: Meteor showers are supposed to come from comets, but
> 3200 Phaethon seems to be an asteroid. It is rocky (not icy, like a
> comet) and has no obvious tail. Officially, 3200 Phaethon is catalogued
> as a "PHA" - a potentially hazardous asteroid whose path misses Earth's
> orbit by only 2 million miles.
>
> If 3200 Phaethon is truly an asteroid, with no tail, how did it produce
> the Geminids? "Maybe it bumped up against another asteroid," offers
> Cooke. "A collision could have created a cloud of dust and rock that
> follows Phaethon around in its orbit."
>
> This jibes with studies of Geminid fireballs. Some astronomers have
> studied the brightest Geminid meteors and concluded that the underlying
> debris must be rocky. Density estimates range from 1 to 3 g/cm3. That's
> much denser than flakes of comet dust (0.3 g/cm3), but close to the
> density of rock (3 g/cm3).
>
> So, are the Geminids an "asteroid shower"?
>
> Cooke isn't convinced. 3200 Phaethon might be a comet after all--"an
> extinct comet," he says. The object's orbit carries it even closer to
> the Sun than Mercury. Extreme solar heat could've boiled away all of
> Phaethon's ice long ago, leaving behind this rocky skeleton "that merely
> looks like an asteroid."
>
> In short, no one knows. It's a mystery to savor under the stars - the
> shooting stars - this Thursday morning.
>
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Received on Wed 13 Dec 2006 12:45:02 PM PST