(meteorobs) OT-Info on Caracas Peru Sept 17, 2007 impact event

[Roberto G.]

From: <meteoreye at comcast.net>


> The recent conference discussed what has been learned so far about the 
> unusual impact event in Peru.
> This info was provided by Jon Clarke, and Austalian Geologist who san eye 
> on these things for me.
> Note quite a few interesting abstracts are linked.
> Wayne
>
> The just finished LPSC had a number of abstracts on last years Carancas 
> impact event.  Given the fact there
> still seems to be some scepticism "out there" regarding this event, here 
> are some links to the abstracts.  The
> authors included researchers from Argentina, Austria, Bolivia, Germany, 
> Japan, Mexico, Peru, the UK,
> Uruguay, and the US.
> Harris et al. PRELIMINARY PETROLOGIC ANALYSIS OF IMPACT DEFORMATION IN THE
> CARANCAS (PERU) CRATERING EVENT. 
> http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2446.pdf
> Prado et al. THE METEORITE FALL IN CARANCAS, LAKE TITICACA REGION, 
> SOUTHERN
> PERU: FIRST RESULTS. 
> http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2555.pdf
> Miura MULTIPLE EXPLOSIONS DURING CRATERING AT CARANCAS METEORITE HIT IN 
> PERU.
> http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2027.pdf
> Schultz et al. IMPLICATIONS OF THE CARANCAS METEORITE IMPACT.
> http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2409.pdf
> Tancredi et al WHAT DO WE KNOW ABOUT THE "CARANCAS-DESAGUADERO" FIREBALL,
> METEORITE AND IMPACT CRATER? 
> http://www.lpi.usra.edu/meetings/lpsc2008/pdf/1216.pdf
> The impact was an ordinary chondrite, class H4 or H5, travelling at 3-6 
> km/s. impacting at an angle of
> 45-60 degrees.  Initial velocities were 12-18 km/s, mostly likely 16 km/s. 
> It is estimated to have had a
> diameter of 1.1 m, a mass of 3 tonnes, and the explosion to have been 
> equivalent to 2 tonnes TNT. No
> fragment larger than a few kg was recovered.  The meteoric material has 
> weathered very rapidly.  The
> impactor's orbit was probably inclined at 25 degrees to the ecliptic and 
> an aphelion inside the orbit of
> Jupiter.
> The crater was 13.6 m in diameter and 1.04 m deep from the ground surface 
> to the submerged floor.
> Water has risen to the ground level.  The rim is between 1 and 3 m high. 
> There was a strong secondary
> steam explosion from shallow groundwater heated by the impact.  The crater 
> was excavated into alluvium
> of a dry stream bed and has a large ray, the rim has classic inverted 
> stratigraphy.  The crater walls have
> slumped significantly because of their wet unconsolidated nature. 
> Numerous microscopic shock
> deformation textures were observed in the ejecta.
> A paper has been submitted to the leading peer reviewed journal Earth and 
> Planetary Science Letters.
> I have access to this at work and will keep people posted.
> Jon

Thank Jon for the links and the news, but I have some questions:

It's wrote that the weight of meteorite was 3 Tn, in the air or at the 
ground?

If the meteorite was of 3 Tn (in the air) how it can to have only 2 Tn of 
TNT, when
for a body with around 20 Km/sec the cinetic energy it's around 60 times
its weight in TNT? (In this case would to be 180 Tn of TNT = 0.18 Kiloton)

The ablation factor should deleted 90-95% of its initial mass, the cosmic 
body
should weight around 30 Tn, but in this case the cinetic energy should be 
1.8 Kilotons

"The crater was 13.6 m in diameter and 1.04 m deep": well, but for to do 
this
we must to have a 0.5 Tn (?) of TNT, how it's possibile a only 2 Tn of TNT
in cinetic energy?

How a meteorite can to go until the ground with an inclination of 45-60° if
a body must to have a inclination of -4°/-6° for to come at the Earth's 
surface?
With the actual theory (as I known) each meteorite (under 100-1,000 Tn)
should burn in the atmosphere.

We have only a very little number of data on the fall of meteorites, 
perharps
they are not corrects?

Best greetings.
Roberto Gorelli