|Speaker:||Gilbert V. Levin, Chief Executive Officer, Spherix (Biospherics), Inc.|
|Topic:||“The Issue of Life on Mars and Its Implications on Science and Philosophy”|
President McDiarmid called the 2127th meeting to order at 8:18 p.m. on February 9, 2001. The Recording Secretary read the minutes of the 2126th meeting and they were approved.
The speaker for the 2127th meeting was Gilbert V. Levin, CEO, Spherix, Inc. The title of his presentation was “The Issue of Life on Mars and Its Implications on Science and Philosophy”.
Contrary to what the speaker, Maxine Singer, said at the last meeting, scientists sometimes change their opinions only very reluctantly. A major shift in our mindset, such as the acceptance of extraterrestrial life in the solar system, may take at least a generation to emerge. The question of life on Mars is now undergoing just such a change in the mindset of many scientists. Until 1997, it was possible to maintain the neutral position that the Labeled Release experiment results of the 1976 Viking mission to Mars were consistent with, but not proof of, a biological response. Other data led to a scientific consensus at the time that a life-mimicking chemical oxidant, not living organisms, had caused the reaction. Now after two decades of laboratory work, reviews of other relevant Viking experiment results, and assessments of new reports on microorganisms found in extreme environments, we should instead conclude that the Labeled Release response was biological. The new argument for this conclusion is that, given the presence of life on Earth, a current absence of life on Mars would be more improbable then its presence. The appearance of life on either planet implies the presence of life on the other.
Begin with the premise that there was no biogenesis on Mars. Given the fact that there is life on earth, what currently accepted science would explain why life had never spread from earth to Mars by interplanetary travel of microorganisms inside rocks, blasted into space by meteoric impact, and freeze dried during transit. Consider the chain of conditions necessary for this version of panspermia. (1) Microorganisms on earth must be widely distributed within rocks. (2) Meteoric impacts must eject rocks and soil with escape velocity into space. Microorganisms within ejecta must survive (3) the shock of ejection, (4) the temperature of atmospheric transit during ejection, (5) the cold, vacuum dehydration, and radiation of travel in space, (6) the shock and temperature of reentry, and (7) the shock and temperature of impact. (8) The surviving microorganisms must then grow in Martian conditions. Finally, (9) the earth and Mars must have been hospitable for such transfers over very long periods.
Condition 1 is now conclusively established, and condition 2 is widely acknowledged. Microbial survival in bullet and vibrating quartz experiments shows that significant fractions should survive condition 3. The fact that some organisms have survived in space shuttle heat shields during reentry shows that condition 4 is not impossible. Survival of condition 5, transit through interplanetary space, can be shown by the fact that some earth microorganisms survived for at least two years on the moon, and others have survived 2 million years in anaerobic permafrost. As for surviving radiation, microorganisms inside rocks would be shielded from damaging UV light, and except for solar flares, they would experience less radiation while in space than in terrestrial environments. That microorganisms can survive a vacuum is evidenced by the fact that vacuum packing is not 100% effective. The conditions for surviving the temperature and shock of reentry and impact are essentially the same as the conditions for ejection. The growth of earth microbes under Martian conditions is severely limited, but not prohibited. Within the past 3.8 billion years when there was life on earth, Mars probably had a warm wet climate for 1 billion years or longer. It is therefore difficult to say why life should not have spread from earth to Mars during that period.
The protocols of the Viking Labeled Release experiments were as follows. Cycle 1, the active experiment, began with an untreated Martian soil sample being added to nutrient containing 14C, and the release of gaseous 14CO2 was monitored for 8 days. Cycle 2, the control experiment, was the same as cycle 1 except that the Martian soil was heated to 160°C for 4 hours before being added to the nutrient. Cycle 3 was a repetition of cycle 1 except that the nutrient was reused from cycle 2. Pre-mission tests using earth samples produced in cycle 1 a steep rise in labeled CO2 production followed by a slower but steady release. In cycle 2 there was a very small rise followed by essentially no further release. The Mars experiments produced a steep rise followed by a plateau in cycle 1, a flat almost zero release in cycle 2, and a result similar to cycle 1 in cycle 3 except that in the plateau phase release continued to rise slowly. At the time, some scientists advanced a non-biological explanation based on the hypothesis that there were heat labile, reactive peroxides in the Martian soil samples.
Before 1997, one argument against life on Mars had been the absence of liquid water. Observations have now established that at one time there was liquid water, perhaps considerable amounts of it, on the surface of Mars. Further, the presence of liquid water to sustain life is not ruled out by the current conditions. The triple point pressure of water is 6 mbar. The pressure on Mars is never less than 7 mbar, so liquid water can form. In the Martian environment if there were frost condensation at night, it would not sublime, but would liquefy and evaporate over about a twenty minute period each morning. Another argument against life, the negative tests from the GC/MS test, cannot be considered conclusive because some vital terrestrial soil samples also tested negative. Because of these new facts, David McKay in a paper to be published March in Lunar and Planetary Science will call for a reexamination of the Labeled Release experiment data.
On the next Mars mission, life detection experiments might include a chiral discrimination control; the initial nutrient would contain L-amino acids and D-sugars, while a second control would be like the first except the nutrient would contain D-amino acids and L-sugars. If the results were reversed or limited compared with the earth comparison results, then life of non-earth origin would be demonstrated.
Mr. Levin kindly answered questions from the floor. President McDiarmid thanked Mr. Levin for the society, and welcomed him to its membership. The President made the announcements about membership, the next meeting, parking, and refreshments, and adjourned the 2127th meeting to the social hour at 9:39 p.m.
|John S. Garavelli|
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