Here's my review of Barry DiGregorio's book.
In it I detail the number of times Levin has been proven right despite wide spread opposition.
For me when a scientist is continually proven right it's for a reason. Not coincidence.
Note in the review one particular argument of Levin is starting in it's foresight: the idea there is in fact water ice quite close to the surface on Mars at the Viking 2 landing site based on the thermodynamic arguments of the temperature measurements.
This has been startlingly confirmed by the GRS instrument on Mars Odyssey. Nobody was making this argument before Levin and it was therefore quite surprising to the GRS scientists when they discovered it.

Bob Clark

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From: Robert Clark (rgclark@my-deja.com)
Subject: Review of Barry DiGregorio's Mars: the Living Planet
Newsgroups: sci.astro, alt.sci.planetary, rec.arts.sf.science, alt.life-mars
Date: 1999/10/13

The following review was posted in the customer reviews on Amazon.com and
BarnesandNoble.com:

In this book DiGregorio admirably discusses evidence for the conclusion that
the Viking missions did in fact discover life on Mars. This is the view of
Drs. Gilbert Levin and Patricia Ann Straat, who developed one of the
instruments, the Labeled Release experiment, that flew on Viking. The book
presents very exciting up to date information on exotic organisms,
extremophiles, that might be found on other planets. NASA itself is
investigating such possibilities with its Astrobiology program. Finally, the
book argues that since some experiments on Viking gave very definite life
signs, missions such as Mars Sample Return should not be undertaken until the
issue is resolved conclusively.

For the last twenty years, Dr. Levin has consistently argued that no
non-biological explanation faithfully reproduces the results seen in his
experiment. Dr. Levin has shown great insight in regards to the life on Mars
issue. As discussed in DiGregorio's book, he suggested to the imaging team
that there were other colors on Mars than just dull browns and reds. This was
verified by members of the Viking imaging team who confirmed there were blue
and green patches on rocks that changed seasonally. Levin argued that the dry
conditions and (apparent) low organic content in the Mars soil did not
preclude the existence of life. Since the Viking missions it has been
confirmed that certain organisms can live within igneous rock surviving on
non-organic chemicals for nutrients and on water that trickles through cracks
in the rock. Levin argued in a paper on liquid water on Mars that a widely
cited paper concluding that liquid water could not exist on the Martian
surface was based on a faulty assumption that water vapor was evenly
distributed through the Martian atmospheric column. The Pathfinder mission
confirmed that water vapor was restricted to the bottom 1 to 3km above the
Martian surface.

Another factor Digregorio discusses in his book is the evidence that there
may be active volcanism on Mars. This is important to the life issue since
this indicates heat and or hydrothemal systems on the Martian surface. And
the National Science Foundation's report on the Mars Sample Return mission
admits that such would increase the chance for life on Mars. Recently from
Mars Global Surveyor images it has been concluded that Mars lava flows could
be as young as 200 thousand years, which would make it virtually certain that
volcanism continues today.

In reading over the history of the controversy over the conflicting results
from the Vking missions, it occurs to me there is a basic flaw in subsequent
investigations to resolve the conflicting results. They all assume there was
something wrong with Levin's Labeled Release experiment and the GCMS, which
indicated no organics on Mars, was right. DiGregorio discusses the fact that
it was first believed there was a problem in the LRx when it gave positive
responses. But the engineering team confirmed it was operating properly. In
contrast, there was one important factor with the GCMS that was definitely
wrong and two others that possibly were wrong. As DiGregorio mentions the
GCMS NEVER GOT AN INDICATION THAT SAMPLES WERE DELIVERED TO THE CHAMBER. This
indicates that either there was a flaw in the mechanism detecting sample
delivery or the GCMS never got a large enough sample to register. If the
second is true then that has clear implications for its failure to detect
organics on Mars. Two other failings of the Viking GCMS is that it could be
"poisoned" by soil with high sulfur content, known to be true of Mars, and
the fact that it could not detect the organic equivalent of fewer than a
million cells per gram.

Given these facts you would think that at least some research would have
gone into showing how the GCMS could have given a wrong result. Yet all the
research (other than Levin's) went to showing why the LRx was wrong. Why?
Scientists are a conservative bunch. Rather than making the truly
revolutionary claim that life had been discovered on Mars, they simply
preferred to make the safe assumption that the instruments indicating life
present were flawed. However, the history of science shows that great
discoveries are made when scientists with insight go beyond the safe
assumptions, and view the evidence dispassionately and go wherever it leads.
What should have given scientists pause is the fact that the conclusion that
the GCMS was right and the LRx wrong was based not on scientific factors but
solely on the assumption that that is the way things should be.

So how can we determine whether it was the LRx or the GCMS that was flawed?
A recent paper by Yen, Murray, and Rossman may give a clue:

Water content of the Martian soil: Laboratory simulations of reflectance
spectra, Authors: YEN, A. S.; MURRAY, B. C.; ROSSMAN, G. R., Journal: Journal
of Geophysical Research, v. 103, No. E5, p. 11,125 (1998).

This paper shows there is a discepancy between the water content of the
Martian soil as determined by the GCMS and determined by all other
Earth-based and orbiter observations, perhaps by a factor of 1 to 2 orders of
magnitude. The upcoming Mars Polar Lander due to land on Mars in December
will test the water content of the Martian soil. If it confirms the high
water content of all other observations than the GCMS then that would
indicate a gross error in the GCMS water analysis and by extension in the
organic analysis as well.

Bob Clark

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The cited JGR paper is available online:

Water content of the Martian soil: Laboratory simulations
of reflectance spectra
http://kipuka.gps.caltech.edu/~marssurf/Water/SoilH2O/

The authors suggest an explanation of why the GCMS
results differ from all the other observations in regard
to water content of the Martian soil (they also assume
the GCMS was right.) However, one of the assumptions they
use seems dubius. They assume there would be little water
in the basaltic rock composing the Martian surface.
However, this is not true on Earth and in fact they had
to heat their laboratory samples to remove their water.
Moreover, this is also unlikely on Mars given the large
number of 'fluidized' ejecta around Martian craters that
have been attributed to water within the Martian regolith:

Mars Orbiter Camera high resolution images:
'Fluidized' crater ejecta deposit
http://www.floridatoday.com/space/explore/stories/1998b/08
1598b.htm

--
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"In order for a scientific revolution to occur,
most scientists have to be wrong"
-- Bob Clark
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