The Viking Labeled Release Experiment and Life on Mars. Past life on Mars

pages: 1 2 [3] 4 5 6 7 

Similar pages:

  • label release experiment
  • gcms viking
  • organic matter microorganism
  • viking experiment pyrolysis release

  • How to Link to This Page

    To link to this page from your website, simply cut and paste the following code to your web page.

    It will appear on your page as:

    Past life on Mars The Viking Labeled Release Experiment and Life on Mars, page 3 from


    While the actual data were not presented, it was stated that the spectrum showed "weak bands in the 2850-3000 cm-1 characteristic of the C-H stretch of methylene groups (-CH2-). Consistent with this, (the) C2 (fraction) gave hydrocarbon fragments on pyrolysis and showed aliphatic (sp3) carbon in its 13C CP-MAS NMR spectrum." Thus, organic compounds surviving this rugged digestion were detected in the soil. They were attributed to kerogen and coal refractory to the GCMS pyrolysis. Biological possibilities were discounted although viable microorganisms have been reported23 within anthracite coal taken from deep underground. The purpose of the intensive digestion of the Antarctic #726 was not stated. One must wonder what variety of labile organic compounds were present prior to the digestion.

    When asked how the report of organic matter in ALH84001 could be reconciled with the negative results of the Viking GCMS, a NASA spokesman24 said that the GCMS had been sent to Mars long ago and may not have been sensitive enough to detect the amounts of organic matter in the low microorganism population in the meteorite. The Viking GCMS was reported25 to require organic content equivalent to 106 bacterial cells to obtain a response in its 100 mg soil sample. This is in sharp contrast to the 50-cell sensitivity of the LR. The difference in sensitivities can readily explain the disparate results reported by the two instruments.

    A fresh examination of the Viking Pyrolytic Release Experiment (PR) data26 supplies direct support for the formation and persistence of organic matter on Mars. In the experiment, a sample of soil is taken into a chamber containing simulated martian atmosphere with its CO and CO2 labeled with 14C. The sample is then exposed to simulated martian sunlight to permit any phototrophic microorganisms to photosynthesize and incorporate the label. After an incubation period, the non-incorporated gases are exhausted from the chamber, and the sample is pyrolyzed to release any labeled gas that had been fixed by the microorganisms. The detection of the gas released by the pyrolysis step is evidence for life.

    During the development of the PR instrument, the formation and accumulation of organic matter from CO and CO2 split by the UV of the simulated sunlight posed the serious threat of obtaining a false positive on Mars. The experimenters reported, "About 14 nmoles of 14C organics per gram of volcanic ash shale are formed within 70 hours of irradiation under a realistic simulation of martian conditions."27 This formation of organic matter from simulated martian atmosphere under simulated sunlight was independently confirmed28. The "solution" to the PR false positive problem was to incorporate an optical filter to screen out the UV below 320 nm.

    In its first experiment on Mars, the PR produced a net response of 81 cpm upon pyrolysis of the sample29. Extensive counting rendered a statistical significance exceeding 3 sigma above background and noise for this response. The response, nonetheless, was far short of the pre-mission criteria for life. The PR Experimenter concluded that the signal was of chemical origin.

    Seeking phototrophs, the PR was the most Mars-like experiment (no water was added). This made it difficult to get a response from terrestrial soils. Cultured microorganisms were frequently added to test soils to get a response. The PR operated on the presumption that martian organisms, under their native environment, would produce a response.

    Overlooked until now is the obvious fact that the low, but significant, PR response was from pyrolysis of the organic matter that had been created within the instrument on Mars. The UV filter did not completely eliminate the formation of organic matter. Pre-mission tests30,31 of the PR had shown that, even with the optical filter, organic matter accumulated on sterile test soils. The PR results on Mars indicate that the formation of organic matter is proceeding.

    2. H2O2: The atmosphere of Mars produces H2O232,33. It was theorized34,35 that the H2O2 precipitates onto the Mars soil. The H2O2 and other oxidants produced from it were assumed to be in the soil sample and to have oxidized the LR organic substrates to release radioactive gas. It was proposed36 that the oxidant(s) also released the oxygen detected in the Viking GEx experiment. This oxidative chemistry also was credited with having cleansed the surface of Mars of any organic material, including microorganisms.

    The most telling evidence against the H2O2 theory is in a just-published report37 of very sensitive Earthbased IR telescopic measurements made through the entire column of the martian atmosphere. No spectrographic feature for H2O2 was found. The sensitivity of the instrument reduces the upper limit for H2O2 in the atmosphere of Mars to 30 ppb. Table 2 presents the amounts of martian H2O2 predicted by current leading H2O2 theorists. Sensitive to, or near, these projected amounts, the new experiment seriously weakens the H2O2 theories.

    Other unresolved difficulties have been reported38 for all theories attributing the LR Mars results to H2O2 under martian conditions.

    next page ) page 3 ) page 4
    return to Past life on Mars

    Write new one


    Mayan Gods
    Mayan Geography

    Past life on Mars:
    Ancient Saga
    Life on Mars
    Virtual gambling - online
    Spirit and Opportunity newsline
    The complete original press release of Dr. Gilbert V. Levin

    Nazca Lines