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Re: A Harry Mcsween lecture, and life in a Martion meteorite.

	This past Monday I attended a scientific talk given by Harry 
Mcsween, president of the Meteoritical Society, at the University of 
Wyoming. His address included mineralogical, petrological, and biological 
reasoning on why the theory of life in a martian meteorite may be 
incorrect. Below is a brief summary of his evidence, pieced together from 
his words. Also I would like to note that I, as relayer of this 
information, take no sides in the debate. 
	The first line of evidence presented in this talk was that 
ALH84001 is an igneous rock(once molten). On Earth, there is no 
indication of fossil life in igneous rocks, bacteria, or otherwise. If a 
plaeontolgist wanted to find fossils, they would look in sedimentary 
deposits. Igneous rocks cannot provide the proper enviroment for organism 
preservation. This is a small piece of evidence, which is supported by 
others to follow.
	The next is indigenous polyciclic  aromatic hydrocarbons(PAH's). 
These are basicly an organic compound, that forms as a waste product. It 
was found that these PAH's were abundant in ALH84001,more than just what 
inorganic process could account for, therfore used as evidence of past 
life. However PAH's are the most prevalent compounds found in the 
universe. The enrichment may be due to time in space, after ejection from 
Mars. Also chondrites contain these same PAH's. It has been shown 
recently(late 1996) that the PAH's were terrestrial contaminents. PAH's 
on Earth form from car exhaust, candles, and smoke stacks. This report 
shows that the PAH's were added to the meteorite after it landed on Earth.
	Minerlogic data given by the first research team showed a 
euhedral(perfectly formeded) magnitite crystals.It is shown however that 
they are not perfectly formed, and have defects in them on the atomic 
level. This indicates that they were formed at high temperatures, too 
high for life to survive. 
	This leads into the argument that the carbonates are low 
temperature origin as indicated by the first study. Carbonates are rocks 
made of minerals with carbon and Calcium in them(limestone). The defected 
magnitites indicate a vapor cloud formation. In order for this vapor to 
be formed the temperature of the surrounding rock has to be high, over 
200 degrees F. This is way to high for life to survive.
	The actual fossils themselves are too small. They are right at 
the boundry of where biologic functions can occur. Now it must be said 
that bacteria found deep in the Earths crust can become 
dehydrated(shrink) and come close to this size, but this is rare. What 
the fossils may actualy be are, the defected magnitite grains. The 
defected magnatite forms screws that are almost identical to what is seen 
in the photos we all have viewed. Now the fossils look to be all going one 
direction, rarely ever does this happen, unles the fossil was in a strong 
current shortly after death. This can be explaned easily, by the 
magnitite, because when minerals form, the tend to form preferentialy.
	This is just a short summary of a larger body of evidence. I 
tried to present the main points, but invariably left something out. 
If you have questions let me know, as I can explain one aspect greater, 
than the sum total of information. 

Frank Stroik
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