[meteorite-list] Comet Holmes
From: Jerry <grf2_at_meteoritecentral.com>
Date: Mon, 29 Oct 2007 20:00:58 -0400 Message-ID: <83B1963A676B4A26A2F95AD35008ACC8_at_Notebook> Offering arguments to account for reality, i.e.. observed phenomenon, where logic is fully implemented, when other KNOWN probabilities, i.e. solar excitation [at least in the present (12 min.)] are eliminated or at the very least, less likely than alternatives, NO MATTER THE MATHEMATICAL ODDS, would lend itself to collision. I suggested this the first night this Comet entered the List discussion. Sterling's "accompanying" fragments does nicely provide a credible suggestion to explain the repetitious nature of the event, BUT passage through SPACE, as EMPTY as it is does not preclude the possibility of getting wacked twice in 100+ years. Jerry Flaherty ----- Original Message ----- From: "Chris Peterson" <clp at alumni.caltech.edu> To: <meteorite-list at meteoritecentral.com> Sent: Monday, October 29, 2007 7:08 PM Subject: Re: [meteorite-list] Comet Holmes >I don't disregard the possibility of collisions with co-orbiting material. >But the probability of colliding with something while passing through the >asteroid belt is still exceedingly small. That zone is still basically >empty space- very little material spread out in a massive volume. > > Chris > > ***************************************** > Chris L Peterson > Cloudbait Observatory > http://www.cloudbait.com > > > ----- Original Message ----- > From: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net> > To: "Chris Peterson" <clp at alumni.caltech.edu>; > <meteorite-list at meteoritecentral.com> > Sent: Monday, October 29, 2007 4:07 PM > Subject: Re: [meteorite-list] Comet Holmes > > >> Hi, Chris, List >> >>> The best argument against a collision is the absurd >>> improbability of TWO collisions in the last century, >>> since this comet has a history of outbursts. >> >> The problem with probability is the probability of the >> assumptions that are applied. If 17P is an isolated object >> and any impactor must come from another unrelated orbit, >> the likelihood of any collision, ever, is very, very low. >> >> Like all short period periodic comets, it is assumed >> that 17P was perturbed into its present orbit, probably >> by Jupiter. Since its orbit ranges from Jupiter to Mars >> and is inclined to the solar system plane, 17P must transit >> the Asteroid Zone twice every orbit (i.e., every 3.5 years). >> One might pass harmlessly through the Zone at many >> locations; at other places, you might not be so lucky. >> >> If 17P is undergoing an on-going disintegration (from >> a past major impact, perhaps very long ago), it may well >> share its orbit with many smaller, darker (harder) fragments, >> millennia-worth of its own "space-junk," a debris stream, >> possibly arising from this ancient impact or partial breakup. >> This would raise the probability of future "trouble" from >> near zero to near 1.0. There may be more than one debris >> stream accompanying it, braided around the principal orbit, >> with objects distributed along the stream. Such streams >> would be quite invisible to us. In the case of Holmes, the >> odds of an outburst per orbit seem to be 12 to 1 against. >> >> Collisions with co-orbiting objects occur at very small >> velocity differentials (from the speed of a man walking >> briskly up to that of a fast runner). Such collisions are not >> catastrophic but damaging: gouging, ripping, crushing, >> crust-breaking, volatile churning affairs. Once a century >> is not that unlikely for such glancing impacts if there enough >> co-orbiting fragments (especially the more silicate ones). >> >> On the other hand, there may be no external impact event >> responsible; it may be the result of some endogenous process >> we do not understand. Whipple began the creation of models >> that explain comet behavior and self-modification of their orbits, >> the effects of thermal exposure, and so forth, and these models >> have been greatly elaborated over the years, yet we cannot >> explain much of comet behavior. Whipple suggested that Holmes >> had been a "double" comet in which the pairs collided. >> >> Holmes is a prime example of this. We think that it never gets >> close enough to the Sun to explain the outbursts, but both the >> discovery outburst and the present one occured after perihelion >> passage with some delay. In both the discovery brightening and >> the present one, the delay was five months! (June 16, 1892 to >> November 6, 1892 -- 143 days; with a second outburst of equal >> brilliance 60 days later. May 4, 2007 to October 24, 2007 -- >> 173 days. A 60-day second outburst would make Holmes >> a Christmas Comet.) >> >> Does perihelion warming trigger some internal mechanism >> that takes about five months to "boil up"? Or does Holmes catch >> up with a stream of significant debris (a collisional association) >> about five months after perihelion and sometimes interact >> collisionally with it? > > ______________________________________________ > Meteorite-list mailing list > Meteorite-list at meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Mon 29 Oct 2007 08:00:58 PM PDT |
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