In 1976, the Viking Mission to Mars's Labeled Release life detection
experiment (LR) returned positive results to Earth from a series of
tests of Martian soil. However, a companion experiment, Viking's Gas
Chromatograph-Mass Spectrometer (GCMS), failed to detect organics in
the Martian soil. Primarily because of the GCMS's negative result,
the scientific community attributed the LR response to putative
chemical oxidants on the surface of Mars. Subsequently, a large
number of theories were presented to contraindicate the possibility
that the LR had detected life. Cautious because of the vast
implications of the detection of life on Mars, I and my
Co-Experimenter, Dr. Patricia Ann Straat, stated only that the LR
results were "consistent with a biological explanation." However,
studying the LR and relative data, along with new scientific findings
made on Mars and Earth over the years, I was forced to the conclusion
that the LR had, indeed, detected living microorganisms.
This talk will present the rationale behind the conclusion that the LR found
life on Mars, and show how more recent data have strongly supported and
reinforced it. Direct evidence will be presented refuting the prevalent
theories against the biological explanation of the Mars LR data. The claims
for a highly oxidizing environment will be countered, and data requiring the
long-disputed presence of liquid surface water will be presented. Comments
will also be made on the recent paper, "Possible Biogenic Origin for
Hydrogen Peroxide on Mars: the Viking Results Reinterpreted," by Joop
Houtkooper and Dirk Schulze-Makuch.
The case will be made that it is now more difficult to propose a sterile Mars
than one with living microorganisms, and that Carl Sagan's oft-quoted axiom,
"Extraordinary claims require extraordinary evidence," has been satisfied.
For those still demanding more evidence, a new experiment to provide
unambiguous confirmation of life on Mars is proposed.