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enough to detect low levels of organics. Klaus Biemann, the principal investigator
of the GCMS experiment on Viking, wrote a rebuttal. Because of the simplicity of
sample handling, TV-GC-MS is still considered the standard method for organic
detection on future Mars missions, so Navarro-González suggests that the design of
future organic instruments for Mars should include other methods of detection.
After the discovery of perchlorates on Mars by the Phoenix lander, practically the
same team of Navarro-González published a paper arguing that the Viking GCMS
results were compromised by the presence of perchlorates. A 2011 astrobiology
textbook notes that while perchlorate is too poor as an oxidizer to reproduce the
LR results (under the conditions of that experiment, perchlorate does not oxidize
organics), it does oxidize, and thus destroy, organics at higher temperatures used
in the Viking GCMS experiment (Plaxco and Gross
2011
). Biemann has written a
commentary critical of this Navarro-González paper as well, to which the latter have
replied; the exchange was published in December 2011.
8.5.3.1
Gillevinia straata
The claim for life on Mars, in the form of
Gillevinia straata
, is based on old data
reinterpreted as sufficient evidence of life, mainly by Gilbert Levin. The evidence
supporting the existence of
Gillevinia straata
microorganisms relies on the data
collected by the two Mars Viking landers that searched for biosignatures of life, but
the analytical results were, officially, inconclusive.
In 2006, Mario Crocco, a neurobiologist at the Neuropsychiatric Hospital Borda
in Buenos Aires, Argentina, proposed the creation of a new nomenclatural rank that
classified the Viking landers' results as “metabolic” and therefore belonging to a
form of life. Crocco proposed to create new biological ranking categories (taxa), in
the new kingdom system of life, in order to be able to accommodate the genus of
Martian microorganisms.
Crocco proposed the following taxonomical entry:
Organic life system: Solaria
Biosphere: Marciana
Kingdom: Jakobia (named after neurobiologist Christfried Jakob)
Genus and species:
Gillevinia straata
As a result, the hypothetical
Gillevinia straata
would not be a bacterium (which
rather is a terrestrial taxon) but a member of the kingdom “Jakobia” in the biosphere
“Marciana” of the “Solaria” system.
The intended effect of the new nomenclature was to reverse the burden of proof
concerning the life issue, but the taxonomy proposed by Crocco has not been
accepted by the scientific community and is considered a single nomen nudum.
Further, no Mars mission has found traces of biomolecules.
The only extraterrestrial life detection experiments ever conducted were the
three which were components of the 1976 Viking Mission to Mars. Of these,
only the Labeled Release experiment obtained a clearly positive response. In this
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