ICAMSR - International Committee Against Mars Sample Return


By Dr. Gilbert V. Levin

May 27, 2020

I was an original member of NASA’S Planetary Quarantine Advisory Panel (PQAP). Before and ever since then, I have had a deep interest in avoiding interplanetary cross-contamination with living organisms. My concern was three-fold:

  1. Ethical - not to interfere with another planet’s natural development.
  2. Public health - not to endanger us or Earth’s Biosphere with alien pathogens, and
  3. (I admit of greater personal concern to me) - to prevent any invalidation of the life detection experiment (“Gulliver,” later named “The Labeled Release Experiment - LR”) I was developing for NASA to probe Mars. I feared a positive life test by my experiment might be dismissed by attributing it to viable contaminants brought from Earth.

Indeed, in 1956, NASA established PQAP out of the concerns expressed in 1 and 2 above. In 1958, the international Committee on Space Research (COSPAR) called for the sterilization of any spacecraft destined for Mars. NASA accommodated this request by subjecting it’s two Viking spacecraft to chemical and thermal treatments to reduce the probability of either spacecraft carrying a viable microorganism to one million-to-one. The cost was approximately $250 million, some one-third the cost of the entire mission.

However, after Viking, 1976, no other spacecraft has been terminally disinfected. Thus, the Viking data from Mars are the only pristine data we will ever see from the red planet. AND the LR results were positive for living microorganisms at both landing sites some 4000 miles apart. However, absent the claim of terrestrial contamination, skeptics raised many other issues to explain away the LR discovery of life. Hesitant to make such a claim because of its immense import, I and my Co-Experimenter, Dr. Patricia A. Straat, studied new data from Mars and Earth (the latter mainly the finding of extremophiles living under Mars-like conditions), and, in 1997, concluded that the LR had made that historic discovery. In the 44 years since the LR results came down, dozens of abiotic explanations of the LR Mars data have been proposed. Under NASA support, Dr. Straat and I spent three years seeking a plausible non-biological explanation, in vain. And none of the aforementioned explanations has withstood scientific scrutiny. Even so, NASA continues to deny the Viking LR results as evidence for life. This, despite the fact that the LR results have been heavily re-enforced by continuing data from succeeding missions, especially Curiosity. All elements essential for life have been found in the Martian soil, in which liquid water and complex bio-type organic compounds have also been detected. Absence of the latter two named findings were the principal reasons long-cited against acceptance of the LR data.

Over the years since Viking, the Space Studies Board (SSB) of the National Academy of Sciences, Engineering and Medicine has produced reports on planetary protection. NASA requested the SSB to review the development of the evolving policy. This effort culminated in a report (NASA Planetary Protection Independent Review Board, NASA, 2019). NASA also requested the SSB review that report and an earlier one on planetary protection for consistency, resulting in its current policy.

All of the above is presented to serve as background for NASA’s current “Mars Sample Return Mission (MSR)” and its Artemis program, and to show that NASA is fully aware and appreciative of the contamination problem. This is particularly true in the time of the COVID-19 pandemic that many view as a harbinger of a possibly infected sample from Mars. In fact, this vision might result in the Mars samples being sent to the moon or to the ISS for safer analysis, as I have advocated.

However, the space agency’s actions have so far completely ignore its deeply-expressed concerns of back contamination, as do its plans for its near-term launches to Mars. The Perseverance spacecraft, scheduled to lift-off for Mars in July of 2020, will not have been disinfected, in common, as stated above, with all launches since Viking. COSPAR currently recommends Viking-type treatment of spacecraft exploring possible habitats, even if not bearing life detection instruments. (Category IVc: “... any region of Mars where liquid water occurs or can occasionally occur”). NASA’s procedures constitute a startling violation of NASA’s well-developed and expressed policy.

Dr. Gilbert Levin with Barry E. DiGregorio
Dr. Gilbert V. Levin presenting his evidence for life on Mars at the 2016 40th Anniversary of the NASA Viking mission to Mars. Photo by Barry E. DiGregorio.

Dr. Gilbert Levin with Barry E. DiGregorio
A graphic depicting how Levin’s Viking LR experiment results from Mars compares to a California soil he tested. Photo by Barry E. DiGregorio.

An unseemly, possible explanation of this dichotomy may be the Artemis program itself, a pillar of which is to put humans on Mars. Announcing the possibility of pathogenic microorganisms on that planet would very likely greatly delay that program. The public would not want the pilgrims to Mars to be regarded as expendable. As always, proving a negative, that there are no pathogens on the planet, is impossible, and, especially, if it is acknowledged that microorganisms do exist there. Somehow, it seems more alarming to hazard infection than to risk physical harm. Perhaps, this is because infection can be spread to Earth upon the return of someone from Mars. So the best way for Artemis to go forward is for NASA to say there is no evidence for any extant life. This somewhat conspiratorial explanation may also account for NASA’s failure to send any life detection probe to Mars since Viking.

The best resolution of these intertwined difficulties would be to analyze all available evidence concerning life on Mars, then to send a robotic life detection experiment based on the findings of such a study, and to proceed with Artemis with whatever precautionary steps are indicated by all results. And, yes, humans seeking to land on Mars will be at risk. Weren’t Columbus and his crew?


G. V. Levin
Palm Beach, May 27, 2020

Last updated May 30, 2020.
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