I have had this same discussion with various scientists from the day I returned home from Carancas. All of them said that the models suggested that Carancas could not have been a chondrite, especially one so fragile as that meteorite is. One even emailed me to ask if I was sure that the meteorite fragments we brought home were from this crater, that perhaps we had been somehow scammed, because the models said only an iron meteorite could form a crater this size. This is science at its best, since something clearly happened that it seemed should not happen. It did happen so science now has the opportunity to figure out how and why the models we wrong. This will continue to be one of the more important meteorite falls for a long time. I forget who, but someone on this list called me on calling Carancas a crater-forming meteorite, well, it seems they were wrong! Of course it is a crater. It also seems that the few kilos that came out are all that are going to come out, there is no more material in Peru, other than weathered dust. If you do not have Carancas in your collection, you are doing yourself a disservice. Michael Farmer
--- Michael Murray <[EMAIL PROTECTED]> wrote: > I certainly agree with you Mr Webb. That > willingness to share by > people in the know such as yourself, and Mr. > Matson, and Mr. > Lebofsky, and quite a few others with the wealth of > knowledge, > training and expertise on meteor/meteorite and so > many other related > sciences, is definitely a big plus for the Met-List. > My hat is off > to all of you. And thank you. > Mike in CO > > On Feb 26, 2008, at 3:47 PM, Sterling K. Webb wrote: > > > Hi, All, > > > > The papers on Carancas referred to are this > one... > > > http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1216.pdf > > > > ...and this one: > > > http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2446.pdf > > > > The first paper suggests, by an analysis of > witness reports > > from the surrounding area, an azimuth of 82° and > an altitude > > of 63° for the incoming trajectory, with an > impact velocity of > > 3000 m/sec. Orbital calculations based on this > track suggest > > a body of low inclination (<5° ) but in an orbit > very different > > from known near-Earth asteroids. > > > > An unique, or at least odd, object, with an > unique, or at least > > odd, orbit. It came from somewhere else, folks... > Its strange > > appearance and texture show a very heavily shocked > history. > > > > The second paper, which studies the impact > effects on the > > materials of the locality, suggests that many of > the shock features > > mean a greater impact velocity, perhaps 4000 m/sec > or more. > > > > Their analysis of the stratigraphy of the > crater suggests that > > the "bolide" reached the ground in one piece and > penetrated > > intact to the depth of about 1/3rd of a meter > before "exploding." > > Large overturned blocks of ejecta are "riddled" > (their word) > > with meteoritic fragments ON THE UNDERSIDE. > > > > Both papers are short and sweet (2 pages) and > they are worth > > the read. > > > > We've been having this discussion on the List > about the > > List, and the Carancas story is a perfect example > of the virtues > > of the List and what it can do in its informal > way. The suggestion > > that the "boiling" and odors of the crater were > due the thermal > > dissociation of troilite (which is abundant in the > meteorite) was > > first made here on the List (and first made > anywhere) by member > > Piper R. W. Hollier. > > > > From that, others were able to calculate that > the impact > > velocity had to be in excess of 1611 m/sec, > probably at least > > twice that, to vaporize the troilite -- a figure > that matches that > > calculated in the first paper cited above. > > > > There were arguments presented for a high > altitude angle > > for the impact (later determined to be 63°) and > for an orbit like > > that suggested in that first paper. In fact, a > good deal of this > > information about Carancas presented in these > papers could > > be found, in somewhat more speculative form, on > the lengthy > > and voluminous List discussion of Carancas in the > first weeks > > after the event. > > > > There was nothing else like this List > discussion of Carancas > > going on anywhere else and no other place where > information > > could be found, sifted, and analyzed, or witness > reports could > > be found. There was even a good explanation of how > the > > "bolide" managed to get to the ground in defiance > of "the > > models" which all say, no way. > > > > All I'm saying here is: "Hooray for the List." > There's > > nothing else like it. > > > > > > Sterling K. Webb > > > ---------------------------------------------------------------------- > > > ---------- > > ----- Original Message ----- > > From: "Darren Garrison" <[EMAIL PROTECTED]> > > To: <meteorite-list@meteoritecentral.com> > > Sent: Tuesday, February 26, 2008 10:24 AM > > Subject: [meteorite-list] Carancas in the news > > > > > http://cosmiclog.msnbc.msn.com/archive/2008/02/25/701427.aspx > > > > Meteorites spark mysteries Posted: Monday, > February 25, 2008 8:20 > > PM by Alan > > Boyle > > > > Five months after a meteorite made an > international splash in Peru, > > experts > > are > > suggesting explanations for some of the space > rock's effects - for > > example, > > the > > sickening odor villagers smelled at the crash > site, and the bubbles > > that > > were > > seen emanating from the water-filled crater left > behind. But a > > study due to > > be > > presented next month also raises fundamental > questions about the > > event. In > > fact, > > an international research team declares that the > impact "should not > > have > > happened" at all. > > > > Yet another study sets forth a mystery surrounding > two other > > meteorites > > found in > > Antarctica a couple of years ago. The rocks don't > match any other > > class of > > meteorite - so where did they come from? > > > > The two studies are among hundreds submitted for > the annual Lunar and > > Planetary > > Science Conference, scheduled March 10-14 in > League City, Texas. The > > conference > > offers the cream of the crop in planetary science > - focusing on topics > > ranging > > from the solar wind, to Mercury and Mars, to the > icy dwarfs on the > > solar > > system's edge. > > > > The Peruvian meteorite impact comes in for a fresh > round of scientific > > scrutiny > > in a study submitted by researchers from Brown > University and > > institutes in > > Peru > > and Uruguay. Just after the impact was reported, > some scientists > > doubted > > whether > > a meteorite was actually responsible for the > crater - but subsequent > > analysis > > proved that a stony space rock was involved (as > opposed === message truncated === ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
