Hi Piper and List, That was my first thought as well. And the authors of the paper took it into account and they specifically addressed it :
"The high altitude of the area might have played a role in the outcome of this event, but not a crucial one. Even if the Carancas meteorite had continued to sea level, it still would have produced a significant crater." An Figure is then provided (Fig. 11) that plots the speed of a falling body as a function of the altitude over the ground. It plots two bodies of different masses and drag coefficients. (p 1980) They concluded that altitude did not play a significant factor. So it leaves us to wonder, why did the Carancas body behave differently from what one would expect from a stony chondrite? How did it survive as a coherent mass until impact, given it's pre-atmospheric mass, composition, entry speed, and angle of descent? Those are questions that the paper left unanswered. Best regards, MikeG On 2/24/10, Piper R.W. Hollier <[email protected]> wrote: > Hi Jerry, Mike, and list, > > At 00:01 25-02-10, MikeG wrote: > >> Yes, a very interesting paper. According to the authors, Carancas was >> a true "hyper velocity impact", and the crater is not an explosion >> crater or penetration pit. Which begs the question - why did the >> Carancas impactor behave differently than other stony impactors? > > > If you mean "why was this a hypervelocity impact, when most others are not," > the answer can probably be found in the altitude of Carancas. According to a > posting by Mike Farmer on 5 October 2007: > > The three of us who went to Peru GPS'd the Carancas > > meteorite crater, and all three came up with the same > > altitude, 3,792 meters. It should now be the highest > > meteorite found. > > This is ~11,900 feet. > > I know it was a tad difficult to breath up there. > > Michael Farmer > > At and above that altitude, the air is much less dense than it is closer to > sea level. Not only does the impactor decelerate less than it otherwise > would, but it is also subject to less deceleration force that might > otherwise cause it to break up. > > Best wishes to all, > > Piper ______________________________________________ Visit the Archives at http://www.meteoritecentral.com/mailing-list-archives.html Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
