Posted on 05/07/2006 9:14:17 AM PDT by blam
Big Breakup: That's the way the comet crumbles
Ron Cowen
Scores of telescopes are watching a comet fall apart, and the main show may be only beginning. The comet has already fragmented into at least 59 pieces and may continue to break up as it reaches its position closest to the sun on June 6. In mid-May, the chunks will venture within 11.7 million kilometers of Earth—the closest any comet has come to our planet in 20 years—and the largest fragments should be visible with binoculars.
Called Comet 73P/Schwassmann-Wachmann 3, this body passes near the sun every 5.4 years and has been breaking up for years. But over the past month, the Hubble Space Telescope and other instruments have documented that a few of the 36-or-so biggest chunks have each split into several dozen smaller bits 20 to 30 meters across.
The ongoing breakup attests that the cores of comets "are as fragile as the meringue in lemon-meringue pie," says Casey Lisse of the Johns Hopkins Applied Physics Laboratory in Laurel, Md.
Many short-period comets—those that orbit the sun at least once every 200 years—may end their lives by splitting up, says Hal Weaver of Johns Hopkins.
Infrared images of the comet taken with the Spitzer Space Telescope and released this week show large amounts of millimeter-to-centimeter-diameter dust particles bridging the large fragments. The ejection of millimeter-size dust might be the primary way in which comets lose material and disintegrate, says Spitzer scientist Bill Reach of the California Institute of Technology in Pasadena.
COMETARY SPLIT. Hubble Space Telescope image (top) homes in on a large fragment of Comet 73P/Schwassmann-Wachmann 3. Some 30 subunits that recently broke off this fragment, dubbed B, trail behind it. Infrared image (bottom) taken by the Spitzer Space Telescope shows dust connecting the fragments C (left) and B (upper right). Weaver, et al./NASA; Reach, et al., JPL/NASA
Spectra from Spitzer also reveal that the largest fragment, dubbed C, contains a higher abundance of micrometer-size silicate grains than is typically seen in intact short-period comets, says Cincinnati-based Spitzer scientist Michael Sitko of the Space Science Institute. "The breakup has cracked the comet open like an egg," revealing its interior composition, Sitko says.
Recent Hubble images show that several house-size fragments generated by the breakup of one of the larger chunks, dubbed B, are being pushed in the direction opposite to the sun. Weaver and his colleagues suggest that solar heating has vaporized icy patches on the chunks, jetting them toward the comet's tail.
Solar heating may also be responsible for the comet's breakup. Although this heat isn't likely to penetrate more than a meter beneath a comet's surface, notes Lisse, that might be deep enough if the heat encounters a large crack within a highly porous comet.
Nevertheless, Lisse says that a "great mystery" remains: "How can a body as weak as meringue come together on a kilometer scale, then fall apart?"
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"If they aren't I'm pretty disappointed in them......"
They didn't let you down, posted here on FR:
Former Military Air Traffic Controller Claims Comet Collision with Earth On May 25, 2006
Yup. Clube, Napier and others claim that earth has been repeatedly pounded by the larger elements within these comet trails causing various 'Dark Ages' on earth over the eons. Their excellent book 'Cosmic Winter' covers this in detail.
Big snowball breaking up. Blame global warming.
Fragment 3-BD looks like it's coming pretty close (within 10k miles):
http://neo.jpl.nasa.gov/cgi-bin/neo_ca?type=NEO;hmax=all;tlim=recent_future;dmax=0.1AU;max_rows=200;action=Display%20Table;show=1&sort=dist_min&sdir=ASC
0.04 lunar distance
Err, I mean, as near as 10k miles.
The comet is now behind Earth and catching up to it. The closest approach i about May 12(which allso happens to be a certain old geezers birthday, but we won't go into that...).
So, after May 12, we will be following along the comets tail.Thats when we might get some meteor activity.
It could turn out to be either a complete dud, or in fact one of the most spectacular displays ever. I imagine for every large fragment Nasa says they found, there are a million sand sized grains.
Must be why Art Bell got out of dodge last month!
I'm awaiting the inevitable prediction that a comet fragment will impact the earth on 6-6-06!
Surely someone is predicting this. If not, remember you heard it here first!
Catastrophism ping?Good idea, Blam. This is the latest in a series of articles on this comet, which is now several comets.
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TEOTWAWKI bump.
The remains of the comet will cross the elliptic plane about May 24th. The Earth will reach that region about May 28.
Tonight we're gonna party like it's 1999!!
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