[meteorite-list] Carancas

From: Galactic Stone & Ironworks <meteoritemike_at_meteoritecentral.com>
Date: Wed, 24 Feb 2010 19:04:08 -0500
Message-ID: <e51421551002241604g6cf099f8ue5180d11db34706e_at_mail.gmail.com>

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 <piper at xs4all.nl> 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
Received on Wed 24 Feb 2010 07:04:08 PM PST