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Location: UFOUpDatesList.Com > 2007 > Sep > Sep 26

Re: Closure On Peruvian Meteor Story?

From: Michael Tarbell <mtarbell.nul>
Date: Tue, 25 Sep 2007 16:04:50 -0600
Archived: Wed, 26 Sep 2007 08:30:58 -0400
Subject: Re: Closure On Peruvian Meteor Story?

>Source: National Geographic - Washington, DC, USA


>September 21, 2007

>Meteor Crash In Peru Caused Mysterious Illness


>But the illness was the result of inhaling arsenic fumes,
>according to Luisa Macedo, a researcher for Peru's Mining,
>Metallurgy, and Geology Institute (INGEMMET), who visited the
>crash site.

>The meteorite created the gases when the object's hot surface
>met an underground water supply tainted with arsenic, the
>scientists said.

>Numerous arsenic deposits have been found in the subsoils of
>southern Peru, explained Modesto Montoya, a nuclear physicist
>who collaborated with the team. The naturally formed deposits
>contaminate local drinking water.

>"If the meteorite arrives incandescent and at a high temperature
>because of friction in the atmosphere, hitting water can create
>a column of steam," added Jos=E9 Ishitsuka, an astronomer at the
>Peruvian Geophysics Institute, who analyzed the object.

I find the poisoning via arsenic-tainted water theory
somewhat problematic (see below), and indeed it
seems to be undermined later in this same article:

>Water samples at the crater proved normal, but the color and
>composition of soil were "unusual" for the area, Macedo noted.

It isn't clear how they arrived at the arsenic poisoning
conclusion. If in fact high levels of arsenic were found in
urine samples from the victims, it would certainly point in that
direction, although that could also have resulted from chronic
exposure to arsenic-tainted water, which they allege is common
in the area.

Moreover, one must question whether boiling arsenic-tainted
water will actually liberate any arsenic, e.g., boiling salty
water liberates little if any sodium or chlorine, but rather
only water vapor. But supposing the arsenic is indeed released
in this fashion, how much water would be involved? This requires
estimates for both the concentration and toxicity of the

There is extremely heavily arsenic-tainted water in parts of
Bangladesh, where the concentration can reach 1 gm of arsenic
per liter of water (the WHO limit is 0.01 mg/liter). The NOISH
IDHL (Immediate Danger to Life or Health) threshhold for
inhalation of inorganic arsenic is 5 mg/cu.meter. Let us adopt
these as working figures.

If we assume that the 'danger' zone was a hemispherical volume
200 meters in diameter centered at the impact site, the enclosed
volume of air is 2.1 X 10^6 cu.m. The total arsenic required to
produce toxic inhalation levels in this volume would then be
~10.5 kg. At 1 gm arsenic per liter of water, this represents
the vaporization of ~10,500 liters (~2770 gallons) of water.

Even for very moist soils, 10,500 liters of water content
represents at least 100 cu.m of soil. To bring this mass to 100
degC and vaporize its water content requires ~4 X 10^10 joules.
If the heating were 100% efficient, i.e., all kinetic energy of
the impacting body converted directly to heating this isolated
soil mass, and assuming a density for typical chondrites of 3.5
gm/cu.cm, this represents a 1-meter diameter (~1800 kg) impactor
traveling at ~6.7 km/sec. This alone should produce a crater ~27
meters in diameter. See:


Considering that the heating is _not_ 100% efficient (i.e.,
kinetic energy of the ejecta, heat transfer beyond the critical
soil mass, etc), the impactor energy requirements are at least
several times larger than the above, say a factor of 3. Using
the same crater calculation technique, this implies a crater ~33
meters in diameter. Note also that these diameter estimates are
for impact into loose sand... in compact/saturated soil, the
diameters are more than a factor of two larger.

This is substantially larger than most of the more recent
estimates of the actual crater size. The National Geographic
article states that "the resulting crater resembles a muddy pond
measuring 42 feet (13 meters) wide and 10 feet (3 meters) deep".

Based on the above reasoning/hand-waving, I personally find the
arsenic theory marginally plausible, certainly not absurd, but
not compelling (pending release, if ever, of the urine sample
analyses). I have not encountered any evidence or argument that
rules out the small comet theory (see my post of 20 Sep), but it
has troublesome aspects of its own.

In any case, speaking for myself, I have not found completely
satisfactory 'closure' on this incident. Although indications
are that this was not an 'anomalous' event per se, it's fair to
say it was an unidentified flying object, and perhaps not
rigorously identified even now.


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